The Science of Vision, Eye Health & Seeing Better

00:00:00.000 | - Welcome to the Huberman Lab Podcast,

00:00:02.280 | where we discuss science and science-based tools

00:00:04.900 | for everyday life.

00:00:05.920 | I'm Andrew Huberman,

00:00:10.460 | and I'm a professor of neurobiology and ophthalmology

00:00:13.360 | at Stanford School of Medicine.

00:00:15.200 | This podcast is separate from my teaching

00:00:16.940 | and research roles at Stanford.

00:00:18.680 | It is, however, part of my desire and effort

00:00:20.880 | to bring zero cost to consumer information

00:00:23.160 | about science and science-related tools

00:00:25.240 | to the general public.

00:00:26.920 | In keeping with that theme,

00:00:28.360 | I'd like to thank the sponsors of today's podcast.

00:00:31.360 | Our first sponsor is Roka.

00:00:33.240 | Founded by two All-American swimmers from Stanford,

00:00:36.280 | Roka eyeglasses and sunglasses have really been designed

00:00:39.400 | with the utmost care and the utmost attention

00:00:41.560 | to the science of optics and the visual system.

00:00:44.680 | So one of the things I like so much

00:00:46.280 | about Roka eyeglasses and sunglasses

00:00:48.400 | is that they're extremely lightweight.

00:00:50.600 | If you get sweaty, so for instance,

00:00:52.240 | if you wear them while running or walking or hiking,

00:00:54.420 | they don't slip off.

00:00:56.000 | And with the sunglasses, when you're outdoors,

00:00:58.480 | if there's cloud cover or if there's shadows,

00:01:00.960 | or if the day gets brighter or dimmer,

00:01:02.640 | you can still see your surroundings perfectly well.

00:01:05.200 | And that's because the designers at Roka

00:01:07.000 | really understand the way the visual system works,

00:01:09.560 | how it habituates, how it adapts.

00:01:11.760 | You don't need to understand the science behind all that,

00:01:13.560 | but they do, and as a consequence,

00:01:15.380 | the eyeglasses perform extremely well under all conditions,

00:01:18.480 | whether or not that's indoors or outdoors.

00:01:21.460 | So they put a ton of science and purpose into the design.

00:01:23.880 | They also happen to look really good.

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00:01:27.040 | A lot of, as you know, performance,

00:01:29.120 | active wear eyeglasses look rather ridiculous,

00:01:32.260 | but the Roka glasses, I think,

00:01:33.960 | have a very nice aesthetic to them

00:01:35.720 | that you could wear anywhere.

00:01:37.000 | If you'd like to check out Roka glasses,

00:01:38.600 | you can go to Roka, that's R-O-K-A dot com,

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00:01:52.320 | Today's podcast is also brought to us by Inside Tracker.

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00:04:51.280 | We are now beginning a new topic

00:04:53.200 | for the next four to five episodes

00:04:55.360 | of the Huberman Lab Podcast.

00:04:57.600 | Before we move into that,

00:04:59.080 | I want to just briefly touch on a couple of questions

00:05:01.340 | that I got from the last episode,

00:05:03.240 | which was related to the science of endurance training.

00:05:06.380 | I described the four kinds of endurance training.

00:05:08.540 | We posted protocols of the specific four kinds

00:05:11.640 | of endurance training at hubermanlab.com.

00:05:14.320 | Just go to that episode.

00:05:15.400 | You can see the download.

00:05:16.360 | It's a zero-cost PDF.

00:05:18.240 | I got a lot of questions

00:05:19.920 | about what's called concurrent training,

00:05:22.040 | which is how to program endurance training

00:05:24.840 | if you are also interested

00:05:26.560 | in strength and hypertrophy training,

00:05:28.560 | or how to incorporate strength and hypertrophy training,

00:05:31.280 | which was in the previous episode, with endurance training.

00:05:35.760 | This can all be made very simple.

00:05:38.200 | Ask yourself, what are you trying to emphasize?

00:05:40.360 | And then emphasize that for a 10 to 12-week cycle.

00:05:43.460 | So if you're mostly interested in endurance,

00:05:46.380 | I would say use a three to two ratio.

00:05:48.920 | Maybe get three endurance training workouts per week,

00:05:52.000 | maybe four, and two strength and hypertrophy workouts.

00:05:56.440 | If you're mainly focusing on strength and hypertrophy,

00:05:59.280 | get three or four workouts for strength and hypertrophy,

00:06:02.220 | and do two endurance workouts.

00:06:05.200 | Start with the minimum number of sets that's required

00:06:08.360 | to get the result that you want.

00:06:10.740 | So if you're not accustomed to doing endurance work,

00:06:13.140 | you would start with the minimum number

00:06:14.640 | that's listed on that protocol.

00:06:16.200 | So if it says three to five sets,

00:06:17.520 | you would start with three, maybe even just two,

00:06:20.080 | and then work your way up by adding sets each week.

00:06:24.040 | I do suggest that people get

00:06:25.480 | at least one complete rest day per week,

00:06:27.480 | although I know a lot of people don't like that.

00:06:30.160 | I benefit from that.

00:06:31.060 | I actually benefit from having two complete rest days

00:06:33.240 | each week.

00:06:34.080 | I just continue to make progress that way,

00:06:35.480 | whether or not it's for strength and hypertrophy

00:06:37.480 | or for endurance.

00:06:39.160 | I am a big believer in rest days.

00:06:40.800 | Other people are not.

00:06:41.760 | And those can be active rest days, hiking, relaxing, et cetera.

00:06:45.660 | After a 10 to 12 week cycle,

00:06:47.960 | then I also suggest taking anywhere

00:06:50.200 | from five to seven days completely off.

00:06:52.520 | You can still enjoy life and do things.

00:06:54.140 | I know for you addicted exercisers

00:06:56.540 | that you're going to loathe to do that,

00:06:58.020 | but that's one way to stay injury-free,

00:06:59.660 | keep your joints and tissues healthy over time,

00:07:01.760 | and continue to make progress.

00:07:03.260 | If you don't want to do that week off, don't do it.

00:07:05.260 | None of this is holy.

00:07:06.180 | None of it is a strict prescriptive.

00:07:07.900 | Just ask yourself, what are you going to emphasize?

00:07:09.940 | And emphasize that in terms of the total volume

00:07:12.020 | of workouts that you do, and work up incrementally,

00:07:14.880 | and then move into another cycle.

00:07:17.320 | That's what I suggest.

00:07:18.600 | So go to Hubermanlab.com.

00:07:19.940 | You can get the protocol there.

00:07:21.740 | We are now going to move into a new topic

00:07:23.940 | unrelated to physical performance,

00:07:25.780 | starting with this episode.

00:07:27.500 | And for the next four to five episodes,

00:07:30.460 | we are going to talk all about the senses.

00:07:33.260 | That's sight, eyesight, hearing, touch,

00:07:39.740 | taste, smell.

00:07:41.900 | And we are also going to talk about this critical sense

00:07:44.520 | that we call interoception,

00:07:46.140 | or our sense of our internal real estate.

00:07:49.000 | Now, the reason that we are talking about the senses

00:07:51.720 | is because if you understand

00:07:53.740 | how the senses are perceived, what they're about,

00:07:57.540 | what the underlying cells and connections are about,

00:08:00.940 | you will be in a terrific position

00:08:02.940 | to understand the month's topic that follows,

00:08:06.180 | which is all about mental health.

00:08:08.540 | Now, I want to emphasize that if you're somebody

00:08:11.780 | who doesn't have any trouble

00:08:13.700 | seeing, hearing, tasting, smelling,

00:08:16.740 | and has an excellent sense of interoception,

00:08:19.220 | I do believe that these episodes

00:08:21.860 | will still be very relevant to you

00:08:23.960 | because they have everything to do

00:08:25.300 | with how you move through the world,

00:08:27.440 | how you make sense of information,

00:08:29.820 | and how you organize your thoughts and your emotions.

00:08:33.340 | I also want to emphasize

00:08:34.460 | that we're going to cover a lot of practical tools.

00:08:37.020 | So today's episode is going to be all about vision

00:08:40.020 | and eyesight, a topic that's very near and dear to my heart

00:08:42.760 | because it's the one that I've been focusing on

00:08:44.980 | for well over 25 years of my career.

00:08:48.020 | But we're not just going to get into the mechanistic details

00:08:50.740 | about how light is converted into electrical potentials

00:08:53.740 | and things like that.

00:08:55.020 | We are going to talk about practical tools

00:08:57.900 | that you can and should use

00:09:00.380 | to help maintain the health of your visual system

00:09:03.620 | and your eyesight.

00:09:05.500 | Very often, young people will say, what should I do?

00:09:08.700 | You know, you're always talking about, you know,

00:09:10.640 | neuroplasticity and how it tapers off over time,

00:09:13.320 | but I'm a young person, what should I do?

00:09:15.380 | You should absolutely train and support your eyesight.

00:09:20.460 | In fact, if you're a young person and you see perfectly,

00:09:23.500 | or you feel as if you see the world perfectly,

00:09:26.100 | you are in the best position to bolster,

00:09:29.060 | to reinforce that visual system

00:09:31.140 | so that you don't lose your vision as you age.

00:09:33.980 | In addition, you can leverage your visual system

00:09:36.160 | for better mental and physical performance,

00:09:38.060 | and we're going to talk about that.

00:09:39.640 | If you're somebody who suffers

00:09:40.820 | from a clinical disorder of vision, you have trouble seeing,

00:09:44.220 | or if you need corrective lenses in order to see,

00:09:46.620 | this episode is definitely for you.

00:09:48.360 | And while, of course, I can't make clinical diagnoses,

00:09:51.060 | I can't have a one-to-one conversation

00:09:53.120 | with any of you in this format, nor am I a clinician,

00:09:56.300 | I'm a scientist, not a physician,

00:09:59.220 | I did consult with our chair of ophthalmology,

00:10:02.740 | Dr. Jeffrey Goldberg at Stanford University

00:10:05.100 | School of Medicine, as well as several other people

00:10:07.580 | to really vet the information and make sure

00:10:09.540 | that the protocols that I'm describing

00:10:11.220 | are consistent with the clinical literature.

00:10:13.560 | If you have a severe eye problem,

00:10:14.840 | you should be working with a really good ophthalmologist

00:10:19.560 | and/or optometrist, but certainly an ophthalmologist

00:10:22.700 | who's a medical doctor.

00:10:24.380 | But I do believe that the information

00:10:26.300 | that we're going to discuss today

00:10:27.600 | is going to be relevant to everybody,

00:10:29.260 | and we'll set the stage for the month on mental health.

00:10:32.540 | And mental performance.

00:10:34.460 | So let's get started.

00:10:36.100 | When we hear the word vision,

00:10:37.740 | we most often think about eyesight,

00:10:40.060 | or our ability to perceive shapes and objects

00:10:43.180 | and faces and colors.

00:10:45.000 | And indeed, vision involves eyesight,

00:10:48.100 | our ability to see shapes and objects

00:10:50.120 | and faces and colors and so forth.

00:10:52.440 | However, our eyes are responsible for much more than that,

00:10:57.440 | including our mood, our level of alertness,

00:11:01.280 | and all of that is included in what we call vision.

00:11:05.300 | So I just want to take about three, maybe four minutes,

00:11:08.900 | and talk about how the visual system works,

00:11:11.380 | how it's built, and how you are able to so-called

00:11:15.860 | see things around you.

00:11:17.540 | I also want to describe the ways in which your eyes

00:11:21.220 | and your visual system impact your mood

00:11:24.120 | and your level of alertness.

00:11:25.900 | And then we are going to get right into some protocols,

00:11:28.740 | some specific things that each and all of you

00:11:31.060 | should do if you want to enhance your vision

00:11:35.620 | and maintain your vision as you get older.

00:11:38.480 | And again, if you're a 15-year-old or a 12-year-old,

00:11:42.360 | this episode is especially for you

00:11:43.940 | because your nervous system is far more plastic than mine is.

00:11:47.220 | It's much more amenable to change,

00:11:48.900 | so you can really build a very strong visual system.

00:11:51.820 | And in doing that, and if you adopt specific behaviors

00:11:55.120 | at any age of light viewing at particular times

00:11:58.720 | in particular ways, then you can build an emotional system

00:12:02.420 | that's also reinforced by your visual system.

00:12:04.920 | So let's talk about vision.

00:12:07.000 | What is vision?

00:12:07.840 | Well, vision starts with the eyes.

00:12:10.180 | We have no what's called extraocular light perception.

00:12:15.380 | While it feels good to have light on our skin,

00:12:17.880 | while it feels good to be outside in the sunlight

00:12:20.440 | for most people, the only way that light information

00:12:23.720 | can get to the cells of your body

00:12:25.820 | is through these two little goodies

00:12:27.380 | on the front of your face.

00:12:28.220 | And for those of you listening, I'm just pointing to my eyes.

00:12:31.280 | As many of you have heard me say before

00:12:33.380 | on this and other podcasts, your eyes in particular,

00:12:35.980 | your neural retinas are part of your central nervous system.

00:12:38.940 | They are part of your brain.

00:12:40.280 | They're the only part of your brain

00:12:42.520 | that sits outside the cranial vault.

00:12:44.940 | In other words, you have two pieces of your brain

00:12:47.220 | that deliberately got squeezed out of the skull

00:12:49.760 | during development and placed in these things

00:12:51.640 | we call eye sockets.

00:12:53.000 | There's a genetic program for the specific purpose

00:12:56.260 | of making sure that three little layers of neurons,

00:12:59.320 | nerve cells got squeezed out

00:13:01.680 | and form what are called your neural retinas.

00:13:04.200 | Now the eyes have a lot of other goodies in them

00:13:06.160 | that are very important.

00:13:07.280 | And those are the goodies that we're going to focus on

00:13:09.760 | a lot today.

00:13:11.320 | There's a lens to focus light precisely to the retina.

00:13:15.640 | If you're somebody who requires eyeglasses or contacts,

00:13:18.460 | chances are you don't do that correctly.

00:13:22.320 | And so that's why you use other lenses

00:13:24.480 | like eyeglasses or contacts.

00:13:26.560 | There are also other pieces of the eye

00:13:28.080 | that are designed to keep the eye lubricated.

00:13:30.520 | You also have these things that we call eyelashes.

00:13:32.800 | Most people don't know this,

00:13:34.060 | but eyelashes are there to trigger the blink reflex

00:13:37.960 | if a piece of dust or something gets in front of your eye.

00:13:40.180 | It's a beautiful adaptation of nature.

00:13:42.300 | They aren't just aesthetically nice.

00:13:44.880 | Costello happens to have very long eyelashes.

00:13:46.900 | He gets compliments about this all the time.

00:13:49.280 | Maybe you have long eyelashes.

00:13:50.720 | I don't have particularly long eyelashes,

00:13:52.560 | but the eyelashes are there so that if a piece of dust

00:13:55.360 | or something starts to head towards the cornea,

00:13:57.840 | the eye blinks very, very fast.

00:13:59.640 | It's the fastest reflex you own is your eye blink reflex.

00:14:03.800 | We also have these things called eyelids.

00:14:06.120 | Now, eyelids might seem like the most boring topic of all,

00:14:08.680 | but they are incredibly fascinating.

00:14:10.460 | Today, we're going to talk about

00:14:12.000 | how you can actually use your visual system

00:14:14.720 | to increase your levels of alertness

00:14:17.360 | based on the neural circuits that link your brainstem

00:14:20.960 | with your eyelids.

00:14:22.640 | And no, we are not going to have a blinking contest

00:14:24.800 | because I would win and you would lose,

00:14:26.920 | and that wouldn't be fun for you.

00:14:28.840 | So let's talk about what the eyes do for vision.

00:14:33.840 | Basically, the entire job of the eyes

00:14:36.260 | is to collect light information

00:14:38.600 | and send it off to the rest of the brain

00:14:41.280 | in a form that the brain can understand.

00:14:43.120 | Remember, no light actually gets in

00:14:45.560 | past those neural retinas.

00:14:47.020 | It gets to the neural retina,

00:14:49.060 | and we have specific cells in the eye called photoreceptors.

00:14:52.820 | They come in two different types, rods and cones.

00:14:56.100 | Cones are mainly responsible for daytime vision,

00:15:00.920 | and the rods are mainly responsible for vision at night

00:15:04.540 | or under low light conditions, generally speaking.

00:15:07.200 | So basically what happens is if your eyelids are open,

00:15:12.220 | light comes into the eye, the lens focuses that light.

00:15:17.240 | Light is also just called photons, light energy,

00:15:19.560 | onto the retina.

00:15:20.680 | These photoreceptors, the rods and cones,

00:15:24.780 | have chemical reactions inside them

00:15:26.620 | that involve things like vitamin A,

00:15:28.720 | and that chemical reaction converts the light

00:15:33.840 | into electricity.

00:15:35.480 | Now, that might seem incredibly abstract,

00:15:37.840 | but the way to think about this is very similar to,

00:15:40.260 | for instance, you have touch receptors on your skin,

00:15:42.600 | and when you press on those touch receptors,

00:15:44.560 | they convert pressure, physical pressure,

00:15:47.200 | into electrical information,

00:15:49.240 | and those neurons send it up to your spinal cord and brain.

00:15:51.320 | You can register that somebody or you are touching

00:15:54.280 | the top of your hand, as I'm doing now.

00:15:56.580 | With the eyes and the retina,

00:15:57.840 | it's just that light gets converted

00:15:59.280 | into electrical information.

00:16:01.460 | Within the eye, within the retina,

00:16:03.440 | there are then a series of stages of processing,

00:16:06.800 | and that information eventually gets sent into the brain

00:16:10.840 | by a very specific class of neurons.

00:16:13.400 | I would like you to know the names of these neurons.

00:16:15.820 | They're called retinal ganglion cells.

00:16:17.700 | So the only thing you need to know

00:16:18.940 | about the neuroscience of the eye at this point

00:16:21.240 | are that they're rods and cones.

00:16:22.920 | The cones are involved in bright daytime vision,

00:16:25.900 | and rods are involved in more dusk or nighttime vision,

00:16:28.980 | and you've got these cells called retinal ganglion cells

00:16:32.660 | that send the information off to the rest of the brain.

00:16:35.720 | Now, here's what's incredible.

00:16:37.360 | I just want you to ponder this for a second.

00:16:39.000 | This still blows my mind.

00:16:40.460 | Everything you see around you,

00:16:44.860 | you're not actually seeing those objects directly.

00:16:47.640 | What you're doing is you're making a best guess

00:16:51.040 | about what's there based on the pattern of electricity

00:16:53.920 | that arrives in your brain.

00:16:55.900 | Now, that might just seem totally wild

00:16:57.880 | and hard to wrap your head around,

00:17:00.360 | but think about it this way,

00:17:02.200 | because this is the way it actually works.

00:17:04.640 | Let's take an example of a color like green or blue.

00:17:09.460 | You have cones in your eye that respond best

00:17:14.260 | to the wavelength of light that is reflected off,

00:17:18.080 | say, a green apple.

00:17:19.520 | So you don't actually see the green apple.

00:17:21.200 | What you see is the light bouncing off that green apple,

00:17:24.460 | and it goes into your eye,

00:17:27.120 | and you see it and perceive it as round and green,

00:17:30.960 | but not because you see anything green.

00:17:33.620 | No green light arrives in your brain.

00:17:36.400 | What happens is your brain actually compares

00:17:39.560 | the amount of green reflection coming off that apple

00:17:43.600 | to the amount of red and blue around it.

00:17:47.880 | Well, you might say, "Well, the green apple's sitting

00:17:50.280 | on a brown table or a white surface."

00:17:53.080 | Well, then it will appear very green,

00:17:56.040 | because the amount of wavelength of light for green

00:18:00.080 | is very high, and the amount for red is very low,

00:18:03.980 | and so it looks very green, okay?

00:18:06.720 | So we don't actually see anything directly.

00:18:09.960 | What the brain is receiving is a series of signals,

00:18:13.300 | electrical signals, and it's comparing electrical signals

00:18:16.960 | in order to come up with what we call these perceptions,

00:18:19.100 | like I see something green, a green apple, or I see red.

00:18:21.860 | Let me give you a slightly different example.

00:18:23.760 | If you were to play a key on the piano,

00:18:26.620 | let's say you play, I'm not a musician,

00:18:28.500 | but I'm going to, so hopefully I won't get this

00:18:30.320 | too incorrectly, but let's say you have like E sharp,

00:18:34.260 | and maybe it's on ding, ding, ding, ding, ding.

00:18:36.480 | If the brain gets that signal, it doesn't actually know E.

00:18:41.380 | That's what, it doesn't recognize it

00:18:43.640 | until you were to play another key next to it,

00:18:46.540 | dun, dun, dun, dun, dun.

00:18:47.880 | And what it does is it does the math,

00:18:49.420 | it does the subtraction, and it compares those two.

00:18:53.020 | So when we see something green or we see something red

00:18:55.800 | or we see something blue,

00:18:57.240 | we're not actually seeing it directly.

00:18:58.700 | The brain is making a guess about how green or red or blue

00:19:01.680 | that thing is by comparing what's around it, okay?

00:19:06.680 | And if that seems hard to wrap your head around,

00:19:08.800 | don't worry because we will explain it in more depth

00:19:12.080 | going forward, but I really want people to understand this,

00:19:14.720 | that vision, eyesight is not looking at things directly

00:19:19.720 | and that information getting directly into your brain,

00:19:22.400 | it is translated.

00:19:24.120 | Light information is transformed into electrical signals

00:19:27.320 | that your visual system exquisitely understands.

00:19:29.800 | Now, what does this mean?

00:19:31.200 | Why should you care about this?

00:19:32.520 | Well, if you have a dog like I do or a cat,

00:19:36.240 | they are not colorblind, but they lack the cones

00:19:41.240 | that respond to red, meaning long wavelength light.

00:19:45.140 | So what does that mean?

00:19:46.720 | That means that when they see green,

00:19:48.840 | it's different than the green you see,

00:19:50.900 | not because that apple isn't visible to them,

00:19:55.440 | but because they aren't able to compare it to red,

00:19:58.560 | and you are.

00:20:00.320 | As a consequence, when they look at a green lawn,

00:20:03.160 | it looks more brownish or orange to them.

00:20:06.140 | When you wear a red shirt in front of your dog or cat,

00:20:10.600 | if you see a stop sign and they see a stop sign,

00:20:13.240 | they see orangish brown and you see red,

00:20:16.560 | presuming that you are a trichromat,

00:20:18.400 | meaning you have three color vision.

00:20:20.680 | So this is all to say that every animal

00:20:23.980 | sees the world differently depending on whether or not

00:20:26.840 | they have one or two or three of these different cones,

00:20:29.520 | the red, blue, or green cones.

00:20:31.640 | If you are a mantis shrimp of all things,

00:20:35.660 | you see hundreds of colors that human beings can't see.

00:20:40.660 | Many animals see into visual ranges

00:20:45.980 | that you and I can't see in.

00:20:47.560 | So for instance, a pit viper senses heat emissions.

00:20:50.040 | It literally sees the heat coming off of you

00:20:53.180 | or of an animal that they want to eat.

00:20:55.760 | If you are a ground squirrel, you can see ultraviolet light.

00:20:59.760 | This is going to sound kind of weird,

00:21:00.820 | but ground squirrels actually signal one another

00:21:03.720 | by standing up outside and shining sunlight

00:21:06.740 | off each other's stomachs to each other,

00:21:08.880 | signaling at a distance, just like, you know,

00:21:10.760 | you could signal somebody with a mirror

00:21:12.240 | in sunlight at distance.

00:21:13.960 | There are species of primates,

00:21:15.260 | this isn't very pleasant to think about,

00:21:16.640 | that urinate on their hands

00:21:18.160 | and then wipe it all over their stomach

00:21:19.620 | and then use that sunlight to reflect

00:21:22.180 | different signals to each other.

00:21:23.260 | I don't know what they're saying.

00:21:24.100 | We always assume it's something cute and nice,

00:21:25.680 | but maybe they're insulting each other.

00:21:27.600 | So this actually gets right down to the heart

00:21:30.080 | of these bigger questions like consciousness.

00:21:32.220 | What do we see? What's out there?

00:21:33.920 | How much of life is really accessible to us?

00:21:38.180 | And I could go on and on.

00:21:39.340 | You know, this used to be kind of an obsession of mine

00:21:42.140 | when I was coming up in the field of visual neuroscience

00:21:44.220 | to understand how different animals

00:21:45.800 | see the world compared to us.

00:21:48.340 | You know, I'll give one more example, a diving bird,

00:21:50.660 | you know, a bird that flies over the ocean.

00:21:52.800 | It has an incredible task.

00:21:54.780 | It has to both view the horizon

00:21:56.940 | and it has to view schools of fish.

00:21:58.580 | And then it has to make a trajectory down into the water

00:22:01.860 | and grab one of those fish to eat.

00:22:03.500 | And the water has what's called a refractory index.

00:22:05.840 | It actually shifts like a prism,

00:22:08.580 | the impression or the perception of where that fish is,

00:22:11.380 | right?

00:22:12.220 | If the bird sees the fish right below it,

00:22:14.020 | it has to know, it has to adjust its diving trajectory

00:22:17.940 | just right because it knows that that fish

00:22:20.500 | actually isn't where it sees it.

00:22:22.500 | It's probably a few inches ahead or to the side of that

00:22:25.260 | because of the way that water diverts the image.

00:22:29.160 | If you've ever dropped a coin to the bottom of a pool,

00:22:31.580 | if you go straight down looking at that location,

00:22:34.940 | if you were to look from the top of the pool

00:22:36.340 | and you dive straight down with your eyes closed,

00:22:38.140 | you will miss because the water refracts.

00:22:41.100 | It shifts the visual image.

00:22:43.340 | Well, diving birds have an arrangement

00:22:46.400 | of these retinal cells that communicate to the brain.

00:22:49.580 | That's both a streak to view the horizon

00:22:51.760 | 'cause they need to know where they are

00:22:52.820 | relative to the horizon.

00:22:53.860 | And they have a pupil like we do on the bottom of their eye

00:22:56.500 | so that they can make very accurate dive and attacks

00:23:00.020 | on these schools of fish and catch fish and eat those fish.

00:23:03.420 | We just have pupils in the middle of our eyes.

00:23:05.900 | So there's a ton about the optics of the eye

00:23:08.360 | and the way that it communicates with the brain

00:23:10.500 | that allows us to see.

00:23:12.060 | We could spend hours talking about this,

00:23:13.500 | but what I'd like to embed in your mind

00:23:15.940 | is that what you experience in the outside world

00:23:19.280 | is bottlenecked, it's limited by which wavelengths,

00:23:23.300 | which colors, if you will, of light that you can see,

00:23:26.740 | that your brain is coming up with a best guess

00:23:28.940 | about what's there.

00:23:29.820 | It doesn't actually know what's there.

00:23:32.820 | And that your vision is distinctly different

00:23:36.060 | from say the vision of a dog

00:23:38.100 | or from the vision of somebody who's a dichromat,

00:23:40.180 | meaning they don't have a red cone.

00:23:42.500 | A lot of people, in particular about one in 80 males,

00:23:46.900 | lacks a red cone and therefore sees the world

00:23:49.100 | much the same way that Costello does,

00:23:50.860 | although he sees it from just much lower toward the ground.

00:23:53.820 | So that's what I'd like you to understand

00:23:57.140 | about the way the eye communicates with the brain.

00:23:59.980 | I would also like you to understand

00:24:02.260 | that the brain itself is making these guesses

00:24:06.860 | and that those guesses are largely right.

00:24:10.140 | How do I know that?

00:24:11.660 | Well, they're right because when you reach out

00:24:13.220 | to grab a glass, most of the time you grab the glass

00:24:15.340 | and you don't miss, right?

00:24:17.340 | Most of the time when you make judgments

00:24:19.220 | about the world around you

00:24:20.580 | based on your visual impression of them,

00:24:23.580 | it allows you to move functionally through the world.

00:24:27.240 | But let me give you some examples

00:24:28.640 | of where this guessing is happening right now.

00:24:31.800 | And it's so incredible that to this day,

00:24:34.740 | this still blows my mind.

00:24:35.960 | Cover one eye with one hand.

00:24:38.200 | If you're driving, maybe don't do this.

00:24:40.560 | If you're viewing the world around you,

00:24:42.300 | presumably you can see everything that's out there.

00:24:44.920 | I could do this with one eye or the other eye.

00:24:47.120 | You probably see better out of one or the other

00:24:48.760 | and we'll talk about that.

00:24:50.060 | You have a giant blind spot

00:24:53.840 | in the middle of your visual field.

00:24:56.320 | It's called your blind spot.

00:24:57.600 | It is the spot in which the connections,

00:24:59.560 | the wires from all those retinal ganglion cells

00:25:01.840 | exit the back of the eye and head off toward the brain.

00:25:04.640 | In other words, you are blind for a huge spot

00:25:08.960 | of your central vision, the part of your vision

00:25:10.840 | that's highest acuity, highest detail.

00:25:13.040 | And yet you don't see that ever.

00:25:15.560 | You cover one eye and you see perfectly fine.

00:25:17.880 | And it's not just because your eye

00:25:19.080 | is moving around really quickly.

00:25:20.640 | Your brain is guessing what's in that spot,

00:25:23.900 | which is absolutely incredible.

00:25:25.520 | And so you don't see that blind spot.

00:25:28.120 | This is happening all the time.

00:25:30.300 | Now, when you have two eyes open,

00:25:32.320 | the way that your eyes are positioned in your head

00:25:34.140 | and the way they view the world is such

00:25:35.460 | that they fill in each other's blind spot.

00:25:37.640 | So it's pretty convenient.

00:25:39.420 | But if you cover one eye, that's impossible

00:25:42.520 | and yet you still see the world as complete.

00:25:45.540 | So the brain is doing these incredible things.

00:25:48.360 | It's also creating depth, a sense of depth,

00:25:50.900 | even though what arrives from the retina

00:25:53.400 | is essentially a readout of a two-dimensional flat image.

00:25:56.520 | So it can sense depth.

00:25:57.760 | How do you know depth?

00:25:58.800 | Well, this is very simple.

00:26:01.120 | Things that are closer to you tend to be larger

00:26:03.520 | than things that are far away.

00:26:05.280 | Things that are closer to you tend to look

00:26:07.160 | like they're moving faster.

00:26:08.480 | If you've ever been in a train and you look to your side,

00:26:10.680 | the rungs on a fence or the train tracks going by you,

00:26:14.080 | look like they're going very fast.

00:26:15.280 | If you look off in the distance,

00:26:16.160 | they look like they're moving very slowly.

00:26:18.220 | And there are differences between what's close to you

00:26:22.180 | and what's further away.

00:26:23.320 | So a little house on the horizon,

00:26:24.880 | you don't look at and say,

00:26:25.720 | "Oh, that must be a tiny little house."

00:26:27.700 | You have some prior knowledge

00:26:29.240 | that things further away are smaller.

00:26:31.660 | So that's the main way that you do that.

00:26:33.120 | And you compare the location at which information

00:26:38.120 | about light lands on the two eyes.

00:26:40.400 | So your eyes are slightly offset from one another.

00:26:43.520 | So that, for instance, if I look at you,

00:26:45.160 | if you were standing right in front of me right now

00:26:46.760 | and I were to look at you,

00:26:48.000 | the image of your face, the light bouncing off your face,

00:26:51.160 | to be more precise, lands on one eye

00:26:53.800 | in a slightly different location

00:26:55.560 | than it does in the other eye.

00:26:56.960 | And then the brain does math.

00:26:59.860 | It basically does the equivalent of geometry

00:27:02.200 | and trigonometry and essentially figures out

00:27:05.880 | how far away you are from me, which is just incredible.

00:27:10.500 | So the brain does all this very, very fast.

00:27:13.040 | And the brain uses about 40 to 50%

00:27:16.160 | of its total real estate for vision.

00:27:19.320 | That's how important vision is.

00:27:20.940 | Now, for those of you that are blind

00:27:22.720 | or low vision or no vision,

00:27:24.460 | that real estate in the brain will be taken over

00:27:27.840 | by neurons that control a sense of touch

00:27:31.160 | and a sense of hearing.

00:27:32.120 | And you're indeed hearing and touch are much better,

00:27:34.800 | higher acuity and faster in blind people.

00:27:39.360 | But for most of you who I presume are sighted,

00:27:42.440 | this is how it works.

00:27:44.140 | So that's kind of vision from eye to brain in a nutshell.

00:27:48.240 | There are a bunch of different stations in the brain

00:27:49.740 | that do different things.

00:27:50.720 | That's eyesight.

00:27:52.480 | Now I want to talk about the other aspect of vision,

00:27:56.460 | which is the stuff that you don't perceive,

00:27:58.720 | the subconscious stuff.

00:28:00.720 | And then we'll transition directly

00:28:02.740 | into how you can use light and eyesight

00:28:05.400 | to control this other stuff, because it's very important.

00:28:08.680 | And that other stuff is mood, sleep, and appetite.

00:28:13.680 | And there are ways in which you can use these same protocols

00:28:17.280 | that I will describe in order to preserve

00:28:20.800 | and even enhance your vision,

00:28:22.520 | your ability to see things and consciously perceive them.

00:28:26.440 | So the protocols we will describe have a lot of carryover

00:28:29.500 | to both conscious eyesight

00:28:32.280 | and to these subconscious aspects of vision.

00:28:35.420 | And I just want you to understand a little bit more

00:28:37.360 | about the science of seeing of eyesight and vision,

00:28:40.440 | and then all the protocols will make perfect sense.

00:28:43.520 | So as amazing as eyesight is,

00:28:45.700 | it actually did not evolve for us to see shapes and colors

00:28:50.000 | and motion and form.

00:28:51.900 | The most ancient cells in our eyes,

00:28:56.040 | and the reason we have eyes,

00:28:58.640 | is to communicate information about time of day

00:29:01.580 | to the rest of the brain and body.

00:29:03.760 | Remember, there's no extraocular photoreception.

00:29:06.040 | There's no way for light information

00:29:07.840 | to get to all the cells of your body.

00:29:10.380 | But every cell in your body needs to know

00:29:12.380 | if it's night or day.

00:29:14.040 | I talked a little bit about this in the episodes on sleep,

00:29:17.940 | and this episode is not about sleep,

00:29:20.600 | but I want to emphasize that there is a particular category

00:29:24.440 | of retinal ganglion cell.

00:29:25.660 | Remember the neurons that connect the retina to the brain

00:29:28.780 | that is involved in a special kind of vision

00:29:32.980 | that has nothing to do with conscious perception

00:29:35.000 | of what's around you.

00:29:36.220 | And it's happening right now.

00:29:37.740 | It's happening all the time.

00:29:39.560 | These are so-called melanopsin retinal ganglion cells

00:29:43.120 | named after the opsin that they contain within them.

00:29:46.220 | They are essentially photoreceptors.

00:29:48.120 | Remember before I said there are photoreceptors

00:29:49.760 | and then these ganglion cells?

00:29:50.740 | Well, these melanopsin cells, as the name suggests,

00:29:54.000 | melanopsin, have their own photoreceptor built inside them.

00:29:58.080 | The opsin that they contain is actually very similar

00:30:03.500 | to the melanopsin that is present in the skin

00:30:07.180 | of some amphibians,

00:30:09.940 | and that causes those amphibians to change their skin color

00:30:14.420 | in different light conditions.

00:30:17.720 | So you have, believe it or not,

00:30:19.820 | a little bit of frog skin in your eye, so to speak.

00:30:24.820 | Okay, not exactly, but you essentially have the equivalent

00:30:28.660 | of what frogs have in their skin in your eye.

00:30:31.740 | If you are low vision or no vision,

00:30:35.980 | as long as you have retinas,

00:30:38.800 | it's very likely you still have these cells,

00:30:41.040 | even though you can't see or you don't see well.

00:30:44.380 | These cells, retinal ganglion cells,

00:30:46.440 | communicate to areas of the brain

00:30:49.160 | when particular qualities of light

00:30:51.640 | are present in your environment

00:30:53.140 | and signal to the brain, therefore,

00:30:57.260 | that it's early day or late in the day.

00:31:00.480 | These melanopsin ganglion cells

00:31:03.080 | are sometimes also called intrinsically photosensitive cells

00:31:05.840 | because they behave like photoreceptors.

00:31:08.500 | What do these cells respond to

00:31:10.100 | and why should you care about them?

00:31:11.460 | Well, you should care about them

00:31:12.700 | because they regulate when you'll get sleepy,

00:31:14.700 | when you'll feel awake,

00:31:16.060 | how fast your metabolism is, excuse me,

00:31:19.240 | your blood sugar levels, your dopamine levels,

00:31:22.520 | and your pain threshold.

00:31:24.460 | There are other factors that impact those things,

00:31:27.300 | but they are one of the, if not the most powerful,

00:31:30.380 | determinant of those other things,

00:31:32.860 | like mood and pain threshold,

00:31:34.140 | sleepiness, wakefulness, et cetera.

00:31:37.580 | These melanopsin ganglion cells

00:31:39.820 | have been shown by the Knights Group, N-E-I-T-Z,

00:31:44.820 | up at the University of Washington

00:31:47.340 | and by Samir Hatar's lab and David Berson's lab

00:31:49.740 | and a number of other people's labs,

00:31:51.280 | Sachin Panda, Iggy Provencio, et cetera,

00:31:54.360 | a number of excellent labs in neuroscience

00:31:56.620 | to set the circadian clock and to respond best

00:32:01.460 | to the contrast between blue and yellow light of the sort

00:32:07.340 | that lands on these cells when you view the sun

00:32:12.140 | when it's at so-called low solar angle,

00:32:14.060 | when it's low in the sky,

00:32:15.300 | either in the morning or in the evening.

00:32:18.180 | What does all this mean?

00:32:19.360 | It means, and here's the first protocol,

00:32:21.520 | and you've probably heard me say this before,

00:32:23.900 | but it is appropriate to this episode to say it again.

00:32:26.600 | If you are not viewing the sun, sunlight,

00:32:32.300 | even through cloud cover for two to 10 minutes

00:32:36.100 | in the early part of the day

00:32:37.380 | when the sun is still low in the sky

00:32:39.620 | and doing the same thing again in the evening,

00:32:42.220 | you are severely disrupting your sleep rhythms,

00:32:45.820 | your mood, your hormones, your metabolism,

00:32:49.140 | your pain threshold, and many other factors,

00:32:51.620 | including your ability to learn and remember information.

00:32:54.760 | The most central and important aspect of our biology

00:32:58.460 | and perhaps our psychology as well

00:33:00.420 | is to anchor ourselves in time,

00:33:04.600 | to know when we exist, okay?

00:33:07.360 | It sounds a little bit abstract and philosophical,

00:33:10.720 | but it's not.

00:33:11.560 | And we don't know time as a real thing

00:33:15.520 | because of watches and clocks.

00:33:16.740 | We know time at a biological level

00:33:19.360 | based on where the sun is and where,

00:33:22.320 | which of course is where we are relative to the sun

00:33:25.240 | because the earth is spinning around.

00:33:26.800 | Now, what does this mean for a protocol?

00:33:29.300 | It means see, get that light in your eyes early in the day

00:33:33.620 | and anytime you want to be awake.

00:33:35.140 | So try and get as much sunlight in your eyes

00:33:36.840 | during the day as you safely can.

00:33:38.160 | We'll talk about eye safety this episode in depth.

00:33:41.260 | And the blue light and the contrast of that blue yellow.

00:33:45.820 | Remember, we don't see blue.

00:33:47.380 | This is all subconscious.

00:33:48.900 | This is blue reflections coming off of sunlight.

00:33:51.100 | Blue light, we've been told is so terrible for us.

00:33:53.120 | It is absolutely essential and wonderful

00:33:54.800 | for waking up the brain,

00:33:56.280 | for triggering all sorts of positive biological reactions,

00:33:59.300 | but it needs to be viewed early in the day.

00:34:01.620 | If you can't see sunlight because it's the thick cloud cover

00:34:04.940 | of say, you're in the UK and it's winter,

00:34:08.380 | then artificial lights, especially blue lights,

00:34:11.620 | would be very beneficial to you.

00:34:13.540 | You need a lot of this light and its contrast with yellow

00:34:16.920 | in order to trigger these melanopsin cells,

00:34:19.180 | which would then trigger your circadian clock,

00:34:21.540 | which sits above the roof of your mouth,

00:34:22.700 | which will signal every cell in your body,

00:34:24.780 | including temperature rhythms, et cetera.

00:34:27.060 | So first things first,

00:34:28.420 | your visual system was not for seeing faces, motion, et cetera.

00:34:33.420 | The most ancient cells in your eye,

00:34:36.060 | which are there right now as we speak,

00:34:38.920 | are there to inform your body and brain about time of day.

00:34:43.920 | So you want to get that bright light early in the day.

00:34:46.540 | Absolutely essential, two to 10 minutes.

00:34:48.100 | You can download the light meter app

00:34:50.100 | if you want to measure lux.

00:34:51.700 | When I explained how to do that in earlier episodes,

00:34:54.220 | it got a little convoluted.

00:34:56.060 | Get that two to 10 minutes, ideally without sunglasses.

00:34:59.060 | Now, here's another reason to do this,

00:35:01.460 | and I've never spoken about this before on any podcast,

00:35:04.700 | which is that there have been several studies now

00:35:07.460 | in thousands of subjects exploring what can be done

00:35:11.980 | to prevent myopia, nearsightedness, and other visual defects.

00:35:16.980 | And it turns out in a series of large clinical trials,

00:35:22.480 | the conclusion has emerged that getting two hours a day

00:35:27.000 | of outdoor time without sunglasses, blue light,

00:35:30.360 | this blue light that everyone has demonized,

00:35:32.920 | getting that sunlight during the day for two hours,

00:35:36.340 | even if you're reading other things

00:35:37.960 | and doing other things outside,

00:35:39.920 | has a significant effect on reducing the probability

00:35:44.560 | that you will get myopia, nearsightedness.

00:35:47.480 | Now, whether or not that's also due to the fact

00:35:50.780 | that myopia can be caused by viewing things

00:35:52.840 | up close too much, so if you're indoors,

00:35:55.500 | we tend to be looking at things more closely, right,

00:35:57.300 | unless you have a very large house

00:35:58.700 | with walls that are very far away from you.

00:36:00.860 | But the effect does seem to be directly related

00:36:04.760 | to getting sunlight and not just to the distance

00:36:07.360 | that you're viewing.

00:36:08.720 | I'm going to describe this study just briefly,

00:36:10.680 | but this is a second protocol.

00:36:11.980 | So we have one protocol about getting sunlight

00:36:13.660 | to set your circadian clocks, meaning wake you up,

00:36:16.680 | establish your sleep will occur about 12 to 16 hours later.

00:36:20.520 | That's all in the sleep episode,

00:36:21.640 | but also to enhance your mood, to enhance your metabolism,

00:36:24.800 | to optimize your hormone levels,

00:36:26.920 | and to optimize learning and dopamine levels,

00:36:28.960 | this feel-good neuromodulator that's essential

00:36:31.660 | to not getting depressed, et cetera.

00:36:34.780 | But now's a second protocol, which is ideally,

00:36:39.680 | and this includes children,

00:36:40.860 | as long as they're not very small infants,

00:36:43.540 | ideally, we're all getting two hours of outdoor time,

00:36:46.880 | even if there's cloud cover.

00:36:48.660 | Remember, we evolved mostly under outdoor conditions,

00:36:51.980 | not indoor conditions, and no artificial blue light

00:36:55.240 | will not replace this aspect of your visual system

00:36:59.600 | and offsetting myopia.

00:37:01.460 | So I just want to briefly describe this study

00:37:03.240 | because it's a very important one

00:37:04.440 | and I don't think it's discussed often enough.

00:37:07.020 | There are many studies exploring this,

00:37:08.520 | but one of the ones I like the most looked at 693 students

00:37:13.520 | and a subset of them were encouraged

00:37:17.780 | to spend 11 hours a week outdoors, okay?

00:37:21.080 | So most kids are in school five days a week or so,

00:37:24.500 | so they're spending 11 hours a week outdoors.

00:37:27.060 | They are sometimes reading outdoors.

00:37:28.400 | They're not always just playing outdoors.

00:37:29.800 | They might be reading books, et cetera.

00:37:33.000 | They used eight different schools,

00:37:36.320 | and the reason they did this study,

00:37:37.620 | I probably should have mentioned,

00:37:38.520 | is that myopia, nearsightedness, is a global epidemic.

00:37:41.520 | At least that's how it was referred to in the study.

00:37:43.820 | I don't know who decides what's an epidemic or not.

00:37:46.020 | I think there are thresholds for that.

00:37:47.920 | This paper published in the journal Ophthalmology in 2018

00:37:53.940 | described the fact that being outdoors for two hours a day

00:37:58.580 | could significantly reduce the probability

00:38:01.340 | that these children would develop nearsightedness.

00:38:04.580 | And it turns out, based on other studies,

00:38:07.020 | that adults who spend two hours a day outside,

00:38:10.460 | so that would be reading outside, talking outside,

00:38:13.380 | no, it does not include light coming

00:38:15.140 | through the windshield of your car.

00:38:16.620 | I'll explain why in a few moments.

00:38:18.360 | Offset the formation of myopia.

00:38:23.540 | Now, myopia or nearsightedness has to do

00:38:25.860 | with the way that the lens focuses light onto the retina.

00:38:30.860 | I don't want to get into a long description of this now,

00:38:33.540 | but basically the lens has to bring light to the retina,

00:38:37.100 | not in front of it, not behind it.

00:38:39.500 | If it brings light to a position in front of the retina,

00:38:43.220 | then you won't see clearly.

00:38:44.740 | You will need corrective lenses.

00:38:47.020 | If it brings light directly to the retina,

00:38:48.900 | then you will see clearly.

00:38:50.180 | That should be intuitive why that makes sense.

00:38:53.180 | So you might say, why would being outside,

00:38:55.300 | getting this blue light or this blue-yellow contrast

00:38:58.660 | from sunlight actually offset myopia?

00:39:02.540 | Well, it probably, and I want to emphasize probably,

00:39:05.700 | has to do with the fact that these melanopsin ganglion cells,

00:39:08.340 | these intrinsically photosensitive ganglion cells

00:39:10.120 | are not just responsible for sleep

00:39:13.080 | and talking to your circadian clock,

00:39:14.620 | and that sort of thing.

00:39:15.720 | They also make connections within the retina.

00:39:18.340 | They connect to things like, this is for the aficionados,

00:39:21.420 | the ciliary body, the iris, the muscles,

00:39:25.420 | and the structures within the eye

00:39:26.760 | that actually move the lens and allow you

00:39:30.180 | to adjust your vision to things up close or far away.

00:39:34.220 | And in doing so, they increase or improve the health

00:39:37.980 | of the little tiny muscles within the eye

00:39:40.820 | that move the lens.

00:39:42.860 | And they probably, again, this needs a little bit more work

00:39:46.620 | in order to really tamp down the mechanism.

00:39:48.720 | They're probably also involved in bringing growth factors

00:39:52.700 | and blood supply to the muscles and to the neurons

00:39:57.540 | that are responsible for this focusing mechanism

00:40:01.620 | within the eye.

00:40:02.780 | So remember, your eye is an optical device.

00:40:05.620 | You were born with lenses.

00:40:06.660 | You don't have to use glasses, or maybe you do,

00:40:08.360 | because you have lenses in your eyes.

00:40:10.300 | And those lenses need to move.

00:40:11.780 | It's not a rigid lens like a glass lens.

00:40:14.440 | It's a dynamic lens.

00:40:15.940 | It has little muscles that pull on it and squeeze it

00:40:18.620 | and make it thicker or thinner

00:40:21.420 | as you look at things close and far away.

00:40:23.260 | And I'll describe how that works in a moment.

00:40:25.220 | These melanopsin cells and their activation by sunlight,

00:40:30.100 | completely subconsciously, unaware, you're unaware of this,

00:40:33.500 | promote the health of this system within the eye

00:40:38.180 | and allow you to offset myopia, nearsightedness.

00:40:42.980 | In other words, getting outside for two hours a day,

00:40:46.220 | each day, on average, even if there's cloud cover,

00:40:49.560 | without sunglasses on, will allow you

00:40:53.060 | to offset the formation of myopia.

00:40:56.660 | Now, you might still form myopia

00:40:58.500 | if you have certain structural features

00:41:00.180 | or genetic basis for that.

00:41:01.340 | We will talk about things that you can do as well.

00:41:03.540 | But for everybody, we should be doing this.

00:41:05.820 | And that might seem like a lot,

00:41:07.220 | but this is the way that your visual system works.

00:41:09.620 | Staying indoors, just getting artificial light,

00:41:13.080 | and looking at things up close, leads to visual defects.

00:41:17.700 | It's a form of kind of like visual obesity.

00:41:20.820 | The posture of your visual system, if you will,

00:41:23.580 | is going to be unhealthy if you're just indoors

00:41:26.080 | and you're not getting sunlight early in the day

00:41:28.240 | and for at least two hours per day.

00:41:30.740 | I want to talk a little bit more about how our eyes adjust

00:41:33.820 | to things that are close to us or far away.

00:41:37.100 | This is an absolutely brilliant consequence

00:41:40.220 | of our nature and our design.

00:41:42.660 | And whenever I say nature and design,

00:41:44.640 | people always ask me, "What are you really trying to say?

00:41:47.420 | Are you trying to talk about creators?

00:41:49.920 | Are you talking about intelligent design?"

00:41:51.400 | Look, I want to be very frank with you.

00:41:53.700 | I wasn't consulted at the design phase and neither were you.

00:41:56.980 | And so that is all very interesting,

00:41:59.120 | but it's not the topic of this discussion.

00:42:01.220 | What is clear and what is the topic of this discussion

00:42:05.620 | is that the eye can dynamically adjust where light lands

00:42:10.620 | by moving the lens and changing the shape of the lens

00:42:13.200 | in your eye through a process called accommodation.

00:42:16.740 | And if you understand this process of accommodation,

00:42:19.780 | you not only can enhance the health of your eyes

00:42:22.860 | in the immediate and long-term,

00:42:24.780 | but you also can work better.

00:42:26.800 | You'll be able to focus better on physical and mental work.

00:42:29.900 | You will be able to concentrate for longer.

00:42:32.820 | And I want to emphasize that so much of our mental focus,

00:42:36.980 | whether or not it's for cognitive endeavors

00:42:38.800 | or physical endeavors is grounded

00:42:42.140 | in where we place our visual focus, okay?

00:42:45.180 | What we look at and our ability

00:42:46.960 | to hold our concentration there

00:42:48.900 | is critically determining how we think.

00:42:53.780 | So in other words, if you can hold visual focus,

00:42:56.900 | you can hold mental focus, cognitive focus,

00:42:59.500 | but holding visual focus is challenging.

00:43:01.780 | It's tiring because it requires movement of the lens.

00:43:06.780 | And that movement of the lens requires activation of muscles

00:43:10.180 | and the activation of muscles,

00:43:11.380 | as you know from the physical performance episodes,

00:43:13.900 | if you saw them and even if you don't,

00:43:15.460 | is dictated by neurons.

00:43:17.520 | So what is accommodation?

00:43:19.180 | Well, it's actually very simple and very elegant.

00:43:24.160 | And again, this is another case

00:43:25.880 | where whenever I look at this stuff,

00:43:27.520 | even though I've been looking at it for years,

00:43:29.160 | learning about it for years,

00:43:30.280 | it still boggles my mind that we have these apparati

00:43:33.860 | built into our eyes.

00:43:35.700 | So we have lenses in our eyes

00:43:37.400 | and we have these things called the irises.

00:43:39.700 | You're all familiar with the iris

00:43:40.980 | because you'll see people's pupils get bigger or smaller.

00:43:44.100 | And we intuitively think of eyes as having the pupils.

00:43:47.960 | If you actually draw two circles on a sheet of paper

00:43:52.080 | and they look like two circles,

00:43:53.920 | but if you put little dots in the middle of them,

00:43:55.760 | they look like eyes.

00:43:56.940 | Your brain recognizes those as eyes

00:43:58.780 | because one of the first things you see

00:44:00.080 | when you come into this world are eyes.

00:44:01.960 | And actually if you put the little dots close together,

00:44:04.520 | it'll look kind of wrong, like it's cross-eyed.

00:44:06.760 | And if you put them at different locations

00:44:09.160 | within those two dots, opposing locations,

00:44:11.040 | it'll look Google-eyed.

00:44:12.080 | And so your brain is actually filling in all the face

00:44:14.160 | and other information, even emotional information,

00:44:16.820 | just based on this recognition of eyes.

00:44:19.360 | And so there's clearly, we know this,

00:44:21.600 | there's real estate further up in the brain

00:44:24.720 | that's responsible for analyzing and recognizing faces

00:44:29.340 | and the eyes and the position of these little things

00:44:31.640 | we call irises and pupils, et cetera,

00:44:33.860 | is really important for how we interpret

00:44:36.900 | the status of others.

00:44:39.480 | And that's why it's such a powerful thing

00:44:40.980 | just to put two circles and move the pupils around on paper.

00:44:45.680 | In fact, I want to get into a combination,

00:44:47.960 | but if you think about it,

00:44:49.220 | if one of my pupils was up there

00:44:50.900 | and the other one was down there,

00:44:51.940 | one was really big and one was really small,

00:44:53.600 | that would actually be a sign of pretty severe damage.

00:44:55.940 | If someone gets hit hard on the side of the head,

00:44:58.060 | you'll notice that they shine a light in one eye.

00:45:00.840 | You know why they're doing that?

00:45:01.760 | They're actually looking at the other eye.

00:45:04.360 | When you shine light of the eye,

00:45:05.400 | that pupil constricts to limit the amount of light

00:45:07.800 | that comes in so it doesn't damage the eye.

00:45:09.640 | This also happens when you walk outside and it's bright.

00:45:11.780 | It constricts,

00:45:13.440 | but we have what's called the consensual pupil reflex.

00:45:16.120 | There's a connection deep in the brainstem,

00:45:18.060 | deep back here in the brain near my neck,

00:45:20.460 | that connects the pupil mechanism for the two eyes

00:45:24.000 | and they're looking at the other eye.

00:45:25.040 | And if you shine light in one eye

00:45:27.020 | and that pupil constricts but the other one doesn't,

00:45:29.120 | there's a good chance there's brainstem damage.

00:45:31.580 | This is what they do on the side of a football field

00:45:34.020 | or a boxing match

00:45:35.100 | or if someone unfortunately hits their head.

00:45:37.760 | So two pupils and don't freak out

00:45:39.700 | if one pupil is a little bit smaller than the other,

00:45:42.440 | that doesn't necessarily mean brain damage.

00:45:43.980 | But if you suddenly have one pupil bigger than the other,

00:45:46.860 | you absolutely want to go see a neurologist right away.

00:45:49.820 | So the eyes and the pupils are indicative of things

00:45:52.600 | that are happening deep in the brain.

00:45:54.780 | Now, accommodation is our ability to accommodate

00:45:58.540 | to things that are up close here or further away.

00:46:02.060 | And the way this works is that the iris and the musculature

00:46:06.020 | and a structure called the ciliary body move the lens.

00:46:08.620 | So when you look far away,

00:46:10.740 | okay, when you see things far away,

00:46:13.280 | your lens actually relaxes.

00:46:16.280 | It can flatten out.

00:46:17.900 | So I want you to think about this.

00:46:18.740 | When you look far away,

00:46:20.380 | when it may be anywhere from like 20 feet away from you

00:46:23.720 | out to a horizon that's miles or kilometers away from you,

00:46:27.940 | the lens can just relax.

00:46:29.420 | It can flatten out.

00:46:30.960 | And you'll notice that it actually is relaxing

00:46:33.260 | to look at a horizon.

00:46:35.060 | It's relaxing to look far away.

00:46:36.820 | Whereas if I look at something up close to me,

00:46:38.940 | like this pen or my phone or a computer screen

00:46:41.660 | or this microphone, it takes effort.

00:46:44.820 | You'll sense the effort.

00:46:46.460 | Now, some of that effort is actually eye movements

00:46:48.660 | because you have muscles that can move your eyes

00:46:50.340 | within their sockets.

00:46:52.140 | But a lot of the work, quote unquote, is neural work

00:46:55.640 | of the muscles having to move and contract

00:46:59.280 | such that the lens actually gets thicker

00:47:02.400 | in order to bring the light to the retina

00:47:05.500 | and not to a location in front of it or behind it,

00:47:08.220 | so-called accommodation.

00:47:10.240 | There's also changes in the size of the pupil

00:47:12.300 | as things are closer and further away from you.

00:47:14.760 | In fact, there's a simple way to think about this.

00:47:18.320 | Healthy pupils are going to dilate

00:47:20.920 | when you look at something far away from you.

00:47:23.520 | Now, when you see something that excites you

00:47:25.600 | or stresses you out, your pupils also get big.

00:47:28.200 | Your eyes get wide.

00:47:29.280 | But if you look at something far away,

00:47:33.460 | your pupils are going to dilate.

00:47:35.680 | And when you look at things that are closer to you,

00:47:38.140 | when you move them up close to the pupils

00:47:39.560 | are going to shrink.

00:47:40.600 | That's all part of this accommodation mechanism.

00:47:43.520 | Now, you might say,

00:47:44.960 | why are you telling me about accommodation?

00:47:46.560 | This is crazy.

00:47:47.400 | Why are you telling me about this?

00:47:48.240 | Well, these days, we're spending a lot of time

00:47:51.700 | looking at things, mainly our phones up close

00:47:53.960 | and computers up close, and we are indoors.

00:47:56.760 | If you are a young person,

00:47:57.880 | and even if you are 25 or older,

00:48:00.800 | and you are spending a lot of time

00:48:02.480 | looking at things up close,

00:48:04.280 | and you are not allowing your vision to relax,

00:48:08.160 | in other words, you are not giving your lens

00:48:10.440 | the opportunity to flatten out

00:48:11.820 | and for these muscles to relieve themselves of this work,

00:48:15.040 | you may or may not have migraine headaches.

00:48:17.760 | You may or may not have headaches.

00:48:19.760 | You might, and that could be the cause of those.

00:48:22.600 | But you are also training your eyes

00:48:27.080 | to be good at looking at things up close and not far away.

00:48:32.840 | And as a consequence,

00:48:33.920 | you are reshaping the neural circuitry in your brain,

00:48:37.200 | and it is not good, it is not healthy,

00:48:40.880 | to only look at things up close.

00:48:43.640 | Now, there are a lot of recommendations out there right now,

00:48:45.800 | especially with all the lockdowns of the last 12 to 18 months

00:48:49.560 | that people should look up from Zoom every once in a while,

00:48:51.580 | or maybe now I'm hearing that people should take calls

00:48:53.700 | instead of doing Zoom,

00:48:55.000 | or you should look up from your computer screen.

00:48:56.580 | It's actually not going to solve the problem

00:48:59.680 | just to look up from your computer screen.

00:49:01.620 | You need to go to a window,

00:49:02.860 | you need to look out at a distance.

00:49:05.400 | Ideally, you would even open the window

00:49:08.120 | because those windows actually filter out

00:49:10.480 | a lot of the blue light that you want during the daytime,

00:49:13.400 | a lot of the sunlight.

00:49:14.520 | It's actually 50 times less gets through.

00:49:17.100 | You want to get out onto a balcony.

00:49:18.440 | You want to relax your eyes and look out at the horizon.

00:49:21.540 | You want to go into what's called panoramic vision

00:49:23.400 | and let your vision expand.

00:49:25.000 | You want this lens mechanism to be very elastic.

00:49:28.280 | You don't want it to get stuck in that configuration

00:49:31.200 | of looking at things up close.

00:49:32.300 | Accommodation is a wonderful feature of your visual system,

00:49:35.260 | but you don't want to push that too hard,

00:49:38.160 | too often or for too long.

00:49:40.620 | You want to view the horizon.

00:49:44.000 | You want to get outside,

00:49:45.320 | not just to lighten the load on your mind

00:49:48.720 | or to think about other things,

00:49:49.980 | but to maintain the health of your visual system.

00:49:53.440 | In other words, you want to exercise these muscles

00:49:58.760 | and that involves both the lens moving

00:50:02.140 | and getting kind of thicker and relaxing that lens.

00:50:05.640 | And the relaxation of the lens

00:50:06.920 | is actually one of the best things you can do

00:50:08.560 | for the musculature of the inner eye.

00:50:10.920 | So what's the protocol?

00:50:12.800 | How often should you do this?

00:50:14.920 | You might be surprised,

00:50:15.820 | but for every 30 minutes of focused work,

00:50:19.060 | you probably want to look up every once in a while

00:50:21.200 | and just try and relax your face and eye muscles,

00:50:23.200 | including your jaw muscles,

00:50:24.420 | because all these things are closely linked

00:50:26.360 | in the brainstem and allow your eyes

00:50:28.900 | to go into so-called panoramic vision

00:50:30.580 | where you're just not really focusing on anything

00:50:32.320 | and then refocus on your work.

00:50:34.800 | At least every 90 minutes of looking at things up close

00:50:40.680 | or even if you're looking at a television screen

00:50:43.840 | or you're watching a movie or you're indoors,

00:50:47.040 | for every 90 minutes of that,

00:50:49.140 | you ideally would have at least 20,

00:50:53.480 | probably more like 30 minutes of being outside ideally,

00:50:57.380 | but if you can't be outside, of non up close vision.

00:51:02.040 | Now you might say, "That's impossible.

00:51:03.140 | "How am I supposed to do that?

00:51:04.440 | "I'm in an office or I'm in a building."

00:51:05.940 | Get to a window, get outside if you can do it safely,

00:51:09.520 | get onto a balcony and just let your eyes relax.

00:51:13.900 | Many people are experiencing severe vision problems

00:51:17.020 | because they're not getting enough sunlight during the day.

00:51:20.160 | They have sleep problems

00:51:21.360 | because they're not viewing sunlight early in the day.

00:51:24.640 | And as I've mentioned in previous episodes,

00:51:27.840 | they're getting a lot of artificial stimulation,

00:51:30.140 | artificial light stimulation of the eye

00:51:31.680 | in the middle of the night.

00:51:33.760 | All of this is through the visual system.

00:51:35.880 | So migraines, fatigue, challenges with your eyesight

00:51:40.880 | getting worse as you age or even in young people,

00:51:43.120 | there's at least according to the articles,

00:51:45.520 | they described it as this epidemic of myopia

00:51:48.480 | can largely be dealt with by getting outside,

00:51:52.460 | going into panoramic vision,

00:51:54.280 | experiencing some distance division,

00:51:56.800 | look at things off on the horizon.

00:51:59.000 | If you're walking or hiking or biking,

00:52:00.940 | not looking at your phone the whole time

00:52:02.500 | that you're doing that.

00:52:03.600 | If you're at the bus stop or you're commuting,

00:52:06.240 | certainly not looking at your phone

00:52:07.940 | the entire time you're doing that.

00:52:10.200 | So this is vital.

00:52:11.480 | And I want to emphasize another protocol,

00:52:13.720 | although I don't want to get into it in too much depth

00:52:15.320 | 'cause I want to make sure that I also talk about

00:52:17.500 | a number of other important aspects of the visual system

00:52:19.500 | that are more related to sight.

00:52:21.320 | But getting into optic flow is very important

00:52:25.920 | for de-stressing your system.

00:52:28.220 | When you move through space,

00:52:30.720 | whether or not it's through walking, biking, even swimming,

00:52:34.560 | if it's self-generated optic flow,

00:52:37.480 | so probably not driving or motorcycling,

00:52:40.080 | but yes, bicycling or I don't know, unicycling.

00:52:43.800 | I don't know why I thought about unicycling.

00:52:44.960 | There used to be a graduate student at Stanford

00:52:46.260 | who was a really impressive unicycler.

00:52:47.640 | Those are pretty rare.

00:52:48.740 | As long as it's self-generated optic flow,

00:52:51.920 | meaning you're generating motion of your body

00:52:54.520 | and the visual images around you are passing by on your eyes

00:52:58.800 | that is very good for the visual system.

00:53:00.900 | And it's very good for the mood systems

00:53:02.960 | and the neuromodulator systems of the brain and body

00:53:05.080 | that regulate mood.

00:53:06.280 | This is well-established.

00:53:08.200 | So I'm not telling people to get away

00:53:10.280 | from their phone and their computers.

00:53:11.400 | I spend a lot of time staring at a page,

00:53:13.640 | drawing, writing, texting, et cetera, just like you do.

00:53:16.520 | But we're really talking about some very simple protocols

00:53:20.040 | that aren't just designed to improve your sleep

00:53:22.200 | but are really designed to bolster and enhance your vision.

00:53:26.200 | And of course, because it's this podcast,

00:53:27.980 | we will also talk about things that you can take

00:53:30.120 | to improve your vision.

00:53:31.000 | But if your visual behavior isn't right,

00:53:35.120 | and I do believe we should always start with behaviors

00:53:37.320 | and then think about nutrition, supplementation, et cetera.

00:53:39.880 | If your behaviors around vision aren't right,

00:53:42.120 | you cannot expect to have good healthy eyesight

00:53:45.240 | for a long time, meaning throughout your lifespan.

00:53:48.560 | And if your vision is already poor,

00:53:50.360 | many of these things that I'm talking about today,

00:53:52.820 | perhaps all of them will improve your vision to some degree.

00:53:56.480 | And if your vision is starting to go,

00:53:59.020 | then doing these behaviors is likely to really enhance

00:54:02.500 | the quality of the vision that you will build

00:54:04.920 | and maintain over time.

00:54:06.620 | And all of these are essentially zero cost, okay?

00:54:09.780 | If you live in a very dark environment,

00:54:11.740 | like a cave or outer space,

00:54:14.740 | it's going to be hard to do some of this stuff.

00:54:16.520 | But if you're on planet earth, even if there's cloud cover,

00:54:20.580 | chances are you can do some or most, or even all of these,

00:54:24.020 | some, most, or all days.

00:54:26.060 | What I'm about to describe next is going to seem so silly

00:54:29.280 | on the face of it, but has deep mechanism to support it.

00:54:32.120 | Put simply, when you get tired, your eyelids close.

00:54:37.900 | And when you're alert, your eyelids are open.

00:54:41.300 | That is because you have neurons in your brain

00:54:46.440 | that depending on your level of alertness

00:54:49.080 | will make it easy or hard to keep your eyes open.

00:54:52.160 | Now that's a complete duh,

00:54:55.200 | except that we don't often think about the relationship

00:54:57.300 | between alertness and where we are looking and our eyelids.

00:55:01.400 | Now, I learned this from a colleague of mine in psychiatry

00:55:05.240 | who happens to work on hypnosis.

00:55:06.480 | I'm not going to hypnotize you right now.

00:55:07.920 | That's actually for a future episode.

00:55:10.320 | But what happens when we get tired?

00:55:14.520 | Our eyelids close and our chin moves down.

00:55:17.140 | We tend to nod out this way.

00:55:20.060 | If you have ever been in a classroom,

00:55:22.880 | certainly not one of mine,

00:55:24.040 | but if you've been in a classroom

00:55:25.900 | and the lecture is kind of drawing on or it's the afternoon,

00:55:29.680 | what you'll notice is that a number of students,

00:55:31.200 | their heads are kind of, their eyelids are closing

00:55:35.320 | and their chin is dropping,

00:55:36.480 | and then you'll see a bunch of heads bouncing back up.

00:55:39.160 | I was definitely one of those people in class.

00:55:41.560 | If it was post-lunch in the afternoon, it's warm,

00:55:44.660 | the hum of the air conditioner or whatever it is,

00:55:47.400 | and I just out, okay?

00:55:49.220 | When we're wide awake, the opposite happens.

00:55:53.340 | Our eyelids are open all the way

00:55:56.440 | and our chin happens to be up.

00:55:58.360 | And no, this is not me telling you to have good posture.

00:56:01.260 | However, what I learned from my colleague at Stanford

00:56:04.720 | is that these circuits actually act in loops.

00:56:08.580 | When we look up,

00:56:10.880 | maybe it's because these melanopsin cells

00:56:13.640 | are in the bottom of our retina, they are,

00:56:15.660 | and maybe it's because they're there

00:56:17.220 | in order to view sunlight, which is overhead, which it is,

00:56:21.720 | but that system of alertness

00:56:24.380 | is linked to the position of our eyes.

00:56:26.580 | So when we look up and our eyelids are up,

00:56:28.520 | it actually has a purpose.

00:56:31.520 | It actually creates a wakefulness signal for the brain.

00:56:35.760 | And so while this might seem like the silliest

00:56:37.900 | and simple tool that I might ever describe on this podcast,

00:56:41.260 | if you are feeling tired,

00:56:44.060 | it actually can be beneficial

00:56:45.840 | to the wakefulness systems of the brain,

00:56:47.520 | including the locus coeruleus

00:56:48.900 | and these areas that release norepinephrine

00:56:51.020 | to actually look up, to actually look up toward the ceiling.

00:56:54.620 | You don't want your chin all the way back,

00:56:56.380 | but to look up and to raise your eyes toward the ceiling

00:56:59.500 | and to look up and try and hold that for 10 to 15 seconds.

00:57:02.940 | So this isn't looking up and closing your eyes

00:57:04.760 | like on a nice sunny day, that's relaxing.

00:57:07.120 | This is looking up and actually looking up at the ceiling.

00:57:11.120 | It actually triggers some of the areas of the brain

00:57:13.680 | that are involved in wakefulness.

00:57:15.400 | So if you're somebody who's falling asleep at your work,

00:57:18.220 | this can be very beneficial.

00:57:20.220 | Likewise, many people are looking at their phone all day

00:57:25.220 | and their chin is down,

00:57:28.380 | and then they're sitting at a computer

00:57:29.860 | that's positioned below them

00:57:31.000 | and they're having trouble staying awake or focusing.

00:57:33.980 | It can be very, I tell Costello this all the time

00:57:36.140 | 'cause he's always falling asleep

00:57:37.140 | while he's trying to do his work.

00:57:38.380 | Positioning your computer screen up at eye level,

00:57:42.880 | or sometimes having it actually above eye level

00:57:46.380 | can actually create wakefulness and alertness

00:57:49.100 | for the work that you're going to do.

00:57:50.400 | This is simply because of this connection

00:57:53.220 | between the brainstem circuits and the other neural circuits

00:57:55.920 | that control wakefulness and eyelids opening and looking up.

00:58:00.920 | Okay, so again, it's remarkably simple,

00:58:04.500 | almost laughably simple,

00:58:05.680 | but it's grounded in some of the most hardwired,

00:58:08.600 | meaning present from birth aspects of our neural circuitry.

00:58:12.140 | And norepinephrine released from locus coeruleus

00:58:15.480 | isn't just a mouthful.

00:58:16.940 | It's a really interesting and powerful mechanism

00:58:20.980 | for how the rest of the brain wakes up.

00:58:22.620 | Locus coeruleus hoses the rest of your brain

00:58:25.260 | with norepinephrine in order to wake up those circuits

00:58:28.980 | for work and attention.

00:58:30.220 | And so eyes up is actually a way,

00:58:34.200 | a route into increased alertness.

00:58:36.560 | Eyes down is a route into sleepiness,

00:58:39.500 | into reduced alertness.

00:58:41.520 | And I have only one friend that texts up here,

00:58:45.320 | like on the street, holds his phone up here.

00:58:47.480 | It looks ridiculous.

00:58:49.000 | And yet, if we were trying to create more sense of alertness,

00:58:54.000 | if that's your goal,

00:58:55.300 | positioning computer screens up high, chin up,

00:58:58.520 | looking up if you need to kind of create

00:59:00.400 | an alertness signal,

00:59:01.280 | not always being chinned down and texting

00:59:03.600 | or working into typewriters or reading below us,

00:59:06.760 | is actually going to send a recurring wakefulness signal.

00:59:10.400 | When things are up, we tend to be alert.

00:59:11.820 | When everything's focused down, including our eyes,

00:59:14.160 | it tends to have a more suppressive

00:59:15.680 | or sedative type signaling

00:59:17.440 | to the deeper centers of the brain.

00:59:19.140 | Now, before we move on to the science and tools

00:59:22.120 | and protocols related to pattern vision,

00:59:24.660 | I want to mention another study

00:59:26.060 | that was done by the University of Pennsylvania.

00:59:28.420 | They have a terrific group there that works on sleep

00:59:31.700 | that made an important discovery

00:59:33.380 | that I think everybody should know about,

00:59:35.780 | which is that children that sleep in rooms

00:59:39.920 | that have a nightlight or dim lights

00:59:43.500 | are much more likely to develop myopia, nearsightedness.

00:59:47.540 | Conversely, children that sleep in very dark rooms,

00:59:53.080 | so either very dim nightlights or a complete black,

00:59:57.600 | they have a much lower, statistically speaking,

01:00:01.420 | a significantly lower probability

01:00:03.160 | of developing myopia, nearsightedness.

01:00:06.120 | Now, why is that?

01:00:07.960 | It's because the wavelengths of light that matter

01:00:12.400 | for these melanopsin cells

01:00:14.120 | oftentimes can get through the eyelids.

01:00:17.600 | And that's particularly true

01:00:20.880 | for children and people that have thin eyelids.

01:00:23.760 | Some people, like me, have very thin eyelids.

01:00:26.360 | I've been told this before.

01:00:27.940 | Not many people touch my eyelids,

01:00:30.140 | but among those that have, they have very thin eyelids.

01:00:33.520 | I notice I have very thin eyelids compared to, say, Costello.

01:00:36.780 | Now, Costello's eyes droop.

01:00:38.200 | He can't even close his eyes all the way.

01:00:39.580 | They're so droopy.

01:00:40.620 | But many people have thin eyelids,

01:00:43.620 | and those people are going to be even more prone

01:00:45.660 | to light coming in through the eyelid.

01:00:48.240 | So for parents, for kids, and for adults,

01:00:52.540 | you really want to try to get to a place

01:00:54.940 | where you can sleep in a completely black

01:00:57.380 | or dark environment.

01:00:58.940 | One little exposure to light, no big deal.

01:01:00.900 | But this ties back to the other protocol

01:01:03.600 | that I've described before in the mood and sleep episodes,

01:01:06.420 | which is that viewing light, even a very low intensity,

01:01:10.260 | between the hours of 10 p.m. and 4 a.m.,

01:01:12.420 | it's extremely detrimental to the dopamine

01:01:14.460 | and other mood-producing systems of the brain.

01:01:17.140 | It can negatively impact learning and immunity

01:01:19.700 | and even blood sugar and make people type 2 diabetes prone

01:01:23.360 | by way of communication from these melanopsin cells

01:01:26.120 | to a structure in the brain called the habenula.

01:01:28.660 | Why am I throwing out all this verbiage?

01:01:30.500 | Well, because people have asked for more mechanisms.

01:01:32.420 | So if you really want to know when you look at blue light

01:01:35.200 | or if blue light is getting in through your eyelids

01:01:36.980 | in the middle of the night,

01:01:38.280 | it is likely distorting these lens accommodation mechanism

01:01:42.940 | in the eye and leading to myopia in some cases.

01:01:47.220 | So that's one reason to avoid blue light exposure

01:01:49.640 | and bright light exposure,

01:01:50.480 | even nightlight exposure in the middle of the night.

01:01:52.720 | Viewing any light of bright intensity

01:01:55.320 | between the hours of 10 p.m. and 4 a.m.

01:01:58.000 | on a consistent basis is going to suppress dopamine

01:02:01.000 | because of the way that that light

01:02:02.640 | activates these melanopsin cells

01:02:04.120 | and the habenula and the dopamine system.

01:02:06.720 | So it's all very simple.

01:02:08.640 | Get as much bright light as you can safely, right?

01:02:12.240 | You never want to look at any light so bright

01:02:13.760 | that it's painful to look at during the daytime.

01:02:16.720 | Try and go without sunglasses unless you need them.

01:02:18.920 | Now I wear sunglasses for sake of sport

01:02:21.080 | and sake of when it's really bright out,

01:02:23.140 | but I try to get two hours a day of working outside

01:02:26.200 | or being outside, even if there's cloud cover,

01:02:28.820 | that's going to offset myopia.

01:02:30.680 | It's going to help you get better sleep.

01:02:32.280 | It's going to support mood and metabolism, et cetera.

01:02:35.280 | And at night, if you're sleeping

01:02:37.440 | with a lot of lights in the room,

01:02:38.520 | and especially if there are kids that need a nightlight,

01:02:41.400 | you should try and wean them off that nightlight

01:02:43.860 | because it's going to be beneficial for their vision

01:02:46.040 | to wean them off that nightlight

01:02:47.260 | and put them into a darker environment.

01:02:49.220 | Obviously you want to get them emotionally comfortable

01:02:50.840 | with that first.

01:02:52.440 | Now let's talk about pattern vision,

01:02:54.160 | actual seeing things like faces and colors, et cetera.

01:02:58.000 | I'm presuming that some of you out there are colorblind.

01:03:01.240 | We can all help the red-green colorblind folks out there.

01:03:05.240 | By not using red in slides and diagrams

01:03:08.640 | and on menus and things of that sort,

01:03:10.200 | try and use magenta instead.

01:03:12.000 | They can see the contrast between magenta and green better

01:03:16.440 | than if there's red and green.

01:03:18.960 | So be kind to the colorblind folks out there.

01:03:21.120 | It's actually a fair percentage.

01:03:23.040 | And there are a lot of different kinds of colorblind.

01:03:25.360 | I should just mention some people are true monochromats.

01:03:28.280 | They see the world in black and white.

01:03:29.660 | That's exceedingly rare.

01:03:31.200 | Most colorblind people, colorblind in quotes,

01:03:35.120 | are red-green colorblind,

01:03:36.880 | meaning they lack red-cone photopigment,

01:03:39.640 | meaning they can't see long wavelengths of light,

01:03:42.100 | so they see the world much as a canine or a cat does,

01:03:45.520 | where they don't get the green-red contrast.

01:03:48.160 | That's why we call it red-green colorblind.

01:03:50.500 | They have the green cones,

01:03:51.960 | but they can't do the contrast comparison

01:03:54.000 | that I described at the beginning of the episode.

01:03:56.680 | So use magenta and they will be able to see things.

01:04:00.420 | You wonder why stop signs and stop lights

01:04:02.400 | and things aren't in magenta.

01:04:03.880 | Well, because the world is unkind

01:04:05.360 | to the red-green colorblind individuals

01:04:07.760 | and they have to learn the position

01:04:09.080 | of those lights in the street lights

01:04:11.360 | and they have to learn the shapes of signs,

01:04:13.400 | which they can do readily

01:04:14.320 | and it usually says stop on it as well.

01:04:16.720 | But if you care about colorblind folks, which I do,

01:04:19.600 | then we could all do them a service by,

01:04:21.960 | I think by law actually in the US,

01:04:24.600 | menus are required to be colorblind accessible.

01:04:27.320 | How can you improve your vision?

01:04:31.480 | How can you get better at seeing things?

01:04:33.980 | Well, one way is to make sure that you spend

01:04:36.780 | at least 10 minutes a day total,

01:04:39.360 | at least, viewing things off in the distance.

01:04:42.280 | So that would be well over half a mile or more.

01:04:45.360 | Try and see a horizon.

01:04:46.720 | Try and get your vision out to a location

01:04:50.080 | that's beyond the four walls of your house or apartment

01:04:53.000 | or the doors of your car and the windshield of your car.

01:04:56.660 | I know that can be hard to do, but it's very valuable.

01:04:59.360 | If you live in a city like New York

01:05:00.940 | and it's skyscrapers everywhere,

01:05:02.820 | you've probably experienced

01:05:04.100 | the incredible sense of relaxation.

01:05:06.700 | And it's aesthetically beautiful

01:05:08.060 | when you are walking down one of these long avenues

01:05:10.240 | and you turn,

01:05:11.560 | and I think they have a name for this in New York,

01:05:14.080 | where the sunset is suddenly visible

01:05:17.560 | along a long avenue between some skyscrapers.

01:05:20.320 | And it's just very relaxing to be able suddenly

01:05:22.640 | to see at a distance.

01:05:23.700 | And that's actually because this eye mechanism

01:05:25.880 | relaxing the lens and relaxing some of the musculature

01:05:30.880 | around the eyes.

01:05:32.260 | Send signals deep into the brainstem

01:05:34.020 | that release some of the centers

01:05:35.420 | that are involved in alertness, AKA stress.

01:05:39.060 | And it's very pleasant for a reason.

01:05:40.880 | It's not a placebo effect, if you will.

01:05:45.240 | There are a bunch of neurochemicals

01:05:46.540 | and things that are associated with that.

01:05:48.300 | So try and see at a distance

01:05:49.820 | because it's good for your eyesight.

01:05:51.380 | It'll keep this lens nice and elastic

01:05:54.020 | and the muscles nice and strong that move the lens.

01:05:56.660 | And it has this relaxing component to it.

01:06:00.460 | Now, our visual system is exquisitely tuned to motion,

01:06:05.200 | not just our self-generated motion,

01:06:07.080 | but the motion of things around us.

01:06:08.840 | And one of the things that it does

01:06:11.000 | is something called smooth pursuit.

01:06:13.740 | Smooth pursuit is our ability to track individual objects,

01:06:18.740 | moving as the name suggests, smoothly through space

01:06:21.480 | in various trajectories.

01:06:24.800 | You can actually train or improve your vision

01:06:29.960 | by looking at smooth pursuit stimuli.

01:06:32.980 | And that sounds really boring.

01:06:34.000 | What you can do is, and I'll provide a link

01:06:35.500 | to some that I think are pretty good

01:06:37.060 | that are used in various clinics,

01:06:39.420 | ophthalmology and optometry clinics.

01:06:42.360 | You can actually take a few minutes each day,

01:06:45.000 | or maybe if you don't do it each day,

01:06:46.640 | you could do every third day or so,

01:06:47.880 | and actually just visually track a ball.

01:06:50.460 | Sometimes it's moving in and kind of an infinity symbol.

01:06:52.580 | Sometimes it's more of a sawtooth.

01:06:54.880 | Sometimes it's changing speed.

01:06:56.680 | Sometimes the cue that you're following,

01:06:59.780 | the little target, is dilating and contracting.

01:07:03.340 | This is going to keep the muscles, I want to be clear,

01:07:06.520 | this is going to keep the extra ocular muscles

01:07:09.400 | conditioned and strong,

01:07:11.200 | and allow you to have a healthy, smooth pursuit system.

01:07:15.460 | Remember, the brain follows the eye.

01:07:17.520 | It follows the movements of the eye.

01:07:19.680 | It has to deal with that.

01:07:20.840 | And the neural circuits within the brain

01:07:22.580 | have to cope with changes in smooth pursuit.

01:07:25.560 | So if you're doing a lot of reading up close,

01:07:27.560 | you're not viewing horizons,

01:07:28.680 | you're not getting a lot of smooth pursuit type stimulation

01:07:31.720 | from your life,

01:07:32.900 | or you're just getting it within the confines

01:07:35.920 | of a little box on your phone,

01:07:37.320 | like your smooth pursuit is over millimeters,

01:07:40.540 | or what we always talk in terms of visual angle,

01:07:43.060 | but the amount of degrees of visual angle.

01:07:44.880 | But if you're just looking at smooth pursuit

01:07:46.320 | in this little tiny box on your phone

01:07:48.020 | or on your computer screen,

01:07:49.360 | and you're not looking at objects in your environment,

01:07:51.420 | like swooping birds and things like that,

01:07:52.940 | which I'm guessing many of you

01:07:53.920 | are not spending your time doing,

01:07:55.560 | well, these mechanisms for smooth pursuit

01:07:57.360 | will get worse over time.

01:07:58.420 | Your vision will get worse.

01:07:59.540 | And so while I prefer that people get out

01:08:02.160 | into the real world and experience

01:08:04.080 | smooth pursuit tracking of visual objects,

01:08:07.060 | and maybe it's a good reason to go to a hockey game

01:08:08.800 | or try and keep your eye on the puck,

01:08:11.080 | which I can never seem to do, move so fast.

01:08:13.880 | Or I guess this is a good reason to watch live sports,

01:08:16.520 | if that's your thing,

01:08:17.620 | or watch a tennis match like a cat, like a kitten,

01:08:19.880 | watching the ball go back and forth.

01:08:21.940 | Whatever, watching kids play, it doesn't really matter.

01:08:25.040 | The idea is that you want to use the visual system regularly

01:08:29.960 | for what it was designed for,

01:08:31.020 | and smooth pursuit is a great way to keep the visual

01:08:35.120 | and motion tracking systems of the brain and the eye

01:08:37.420 | and the extraocular muscles

01:08:38.820 | working in a really nice coordinate fashion.

01:08:41.100 | I would say five to 10 minutes, three times a week,

01:08:46.100 | will be great if you care about your vision,

01:08:47.940 | you can train your vision in this way.

01:08:50.180 | The other one is to train accommodation.

01:08:53.540 | There are a lot of videos out there,

01:08:55.180 | I want to be clear, on the internet,

01:08:57.000 | some of which are from clinicians, some of which are not,

01:09:01.320 | some of which are from scientists,

01:09:02.600 | some of which are from other sources,

01:09:04.580 | talking about things you can do to make your vision better,

01:09:08.380 | to improve your vision.

01:09:09.560 | Most of those are geared toward

01:09:12.100 | improving the extraocular eye muscles.

01:09:14.420 | But I did consult with our chair of ophthalmology

01:09:18.120 | at Stanford School of Medicine, Jeff Goldberg,

01:09:20.980 | who's an MD and a PhD, a phenomenal scientist

01:09:23.780 | and a phenomenal clinician,

01:09:25.620 | and incidentally, a phenomenal chairman as well,

01:09:28.360 | about what sorts of things, tools are actually beneficial

01:09:33.180 | for pattern vision and sight,

01:09:35.180 | because there's just so much out there on the internet,

01:09:37.440 | not all of which is accurate or good, frankly.

01:09:40.940 | And he agreed that a smooth pursuit stimulus,

01:09:43.940 | that kind of training, as well as, or exercise,

01:09:47.920 | as well as near far.

01:09:49.700 | So spending a few minutes,

01:09:51.280 | you might even just do this for two minutes,

01:09:52.860 | of looking at something up close,

01:09:54.920 | that's going to activate these accommodation mechanisms,

01:09:57.140 | and then moving it at arm's length

01:09:59.240 | and focusing on it for five, 10 seconds, maybe more,

01:10:01.940 | maybe 15 or 20 seconds,

01:10:03.840 | then slowly moving it into a location and then out.

01:10:07.460 | This is actually a lot like the visual training

01:10:09.700 | that's done post-concussion to try and repair,

01:10:13.740 | actually repair some of the balance and motor

01:10:16.300 | and visual and cognitive aspects of the brain.

01:10:20.340 | And we are going to have a guest on in a future time

01:10:23.100 | that to deal with concussion

01:10:24.580 | and some post-concussion training,

01:10:26.560 | a lot of post-concussion recovery and training centers

01:10:29.160 | around the visual system,

01:10:30.380 | not just because people are trying to recover their vision

01:10:33.780 | and their sense of balance,

01:10:35.540 | but because, as I mentioned earlier,

01:10:37.300 | the brain's ability to make sense of its environment

01:10:40.460 | and the brain's ability to parse time,

01:10:42.840 | not just on the day/night schedule,

01:10:44.800 | but also shorter time intervals, follows the visual system,

01:10:49.220 | something we'll turn to a little bit more at the end.

01:10:51.140 | So what does this mean?

01:10:52.060 | The tool is spend two to three minutes doing smooth pursuit.

01:10:56.840 | There's some programs on YouTube.

01:10:59.000 | You can just look up smooth pursuit stimulus,

01:11:00.840 | and I'll provide a link to a couple I like as well.

01:11:04.220 | You could do this with a pen if you wanted.

01:11:06.600 | You could do this, someone else could hold a wand,

01:11:09.160 | and you could do that

01:11:10.000 | if you've got someone that can do that for you.

01:11:11.540 | Practice accommodation for a few minutes,

01:11:13.260 | maybe every other day, just bringing something in close.

01:11:16.360 | You'll feel the strain of your eyes doing that.

01:11:18.240 | I can feel it right now.

01:11:19.540 | Move it out.

01:11:20.980 | You'll feel a relaxation point.

01:11:22.520 | Move it past that relaxation point

01:11:24.200 | where you will have to do what's called a virgin side movement

01:11:26.220 | to maintain focus on that location as it moves out.

01:11:28.620 | Bring it back in.

01:11:30.060 | At the point where you actually have to go cross-eyed,

01:11:32.720 | this will differ for different people

01:11:33.940 | depending on how far apart your eyes are,

01:11:35.840 | so-called interpupillary distance.

01:11:37.540 | So for me, I have been teased before.

01:11:39.300 | I have a very short interpupillary distance.

01:11:41.480 | I'm not a cyclops, but I'm heading there.

01:11:44.300 | Some people are more wall-eyed like a flounder.

01:11:47.040 | Well, depending on your interpupillary distance,

01:11:49.820 | the point at which things get blurry and cross-eyed

01:11:52.740 | will vary, but for me, you know, as I get about,

01:11:56.600 | oh my gosh, I guess it's about six inches from my nose,

01:11:59.340 | it's really hard, I can't accommodate any longer.

01:12:01.420 | I move it out another inch and everything's in nice focus.

01:12:03.980 | Try and see whether or not you can get things closer.

01:12:05.940 | Now, you don't want to get cross-eyed.

01:12:07.300 | Remember what your parents told you,

01:12:09.020 | or my parents told me that if you cross your eyes

01:12:11.220 | when you're young, that they can stay that way.

01:12:13.500 | Actually, they won't necessarily stay that way,

01:12:16.040 | but your brain can start losing information

01:12:18.940 | and the ability to see binocular depth,

01:12:21.820 | something we'll talk about in a moment.

01:12:22.960 | But for now, the protocol would be two to three,

01:12:26.560 | maybe five minutes, just practice that,

01:12:28.400 | practice accommodation,

01:12:29.400 | and then be sure to give your eyes some rest.

01:12:31.880 | Get outside, look at a horizon, or do nothing.

01:12:34.500 | Just kind of let your eyes go soft.

01:12:36.280 | Guess what the yogis would call soft gaze.

01:12:38.120 | Just kind of relax your eyelids.

01:12:39.760 | Not this, not eyes closed, just relax.

01:12:43.020 | Panoramic vision, try and see the walls around you

01:12:45.060 | without moving your head.

01:12:46.900 | Exercise your eye muscles,

01:12:48.280 | exercise the accommodation mechanisms of your eyes.

01:12:50.940 | Practice a little bit of smooth pursuit.

01:12:53.160 | You don't have to be neurotic about this,

01:12:54.580 | but if you do this often enough,

01:12:56.240 | meaning every other day, every third day or so,

01:12:59.660 | you can be the strange person on the plane

01:13:01.280 | or in the classroom doing this.

01:13:03.460 | People might chuckle or look at you funny or tease you,

01:13:06.360 | but that's okay because you'll be able to see

01:13:08.780 | when they are losing their vision.

01:13:11.040 | So you'll get the last laugh.

01:13:13.000 | Please don't laugh at them,

01:13:13.920 | but maybe you can help them at that point.

01:13:15.420 | You can hold the pen for them.

01:13:16.920 | It's worth doing.

01:13:19.280 | It's really worth preserving your vision.

01:13:21.200 | And again, if you're a young person, this is great

01:13:23.600 | because then you can actually build

01:13:24.920 | an extra strong visual system

01:13:27.260 | using all the tools that we're describing.

01:13:29.600 | I do want to talk about a new set of findings

01:13:33.160 | that are related to red light

01:13:34.920 | and offsetting age-related macular degeneration.

01:13:37.960 | There are a lot of ways in which our visual system

01:13:39.940 | gets worse over time,

01:13:40.780 | but one is so-called age-related macular degeneration.

01:13:44.020 | Glenn Jeffrey at the University College London,

01:13:46.160 | somebody I've known for decades because he's a scientist,

01:13:50.260 | has done beautiful work on development

01:13:52.020 | and function of the visual system,

01:13:53.040 | has published a number of papers recently.

01:13:55.720 | One that got a particularly high amount of attention

01:13:59.600 | in the press was one that showed that flashing red light

01:14:02.520 | into the eyes early in the day, not late in the day,

01:14:05.360 | early in the day can help offset

01:14:08.240 | some age-related macular degeneration,

01:14:11.180 | presumably by enhancing the mitochondrial function

01:14:14.120 | in the photoreceptors.

01:14:15.680 | There does seem to be some evidence for that,

01:14:17.920 | although it's still early days.

01:14:19.480 | I want to emphasize you don't want to shine

01:14:21.760 | really bright lights into your eyes.

01:14:23.200 | You never want to look at any light that's so bright

01:14:25.620 | that it's painful,

01:14:26.860 | and you never want to force your eyelids to stay open.

01:14:28.700 | If you need to close your eyes in order to be comfortable,

01:14:30.980 | well, then chances are that light is too bright.

01:14:33.380 | But doing just a couple minutes a day,

01:14:35.540 | like two minutes a day of flashing this red light

01:14:38.640 | into one eye and then the other,

01:14:40.500 | as long as it was early in the day before noontime,

01:14:44.420 | and as long as it was in individuals

01:14:46.080 | that were 40 years or older,

01:14:48.860 | did seem to have a significant effect

01:14:50.620 | in offsetting some of the age-related macular degeneration

01:14:53.780 | that would otherwise occur.

01:14:55.580 | Again, these are early findings.

01:14:56.860 | If you want to do this, please be careful.

01:14:59.180 | Please talk to your optometrist and/or ophthalmologist.

01:15:02.600 | Your eyesight is precious, you don't want to damage it,

01:15:04.620 | but it is interesting, and it does seem like red light

01:15:07.460 | can improve the function of the mitochondria.

01:15:09.280 | These photoreceptors have a lot of mitochondria,

01:15:11.820 | the energy-producing organelles within the cells,

01:15:14.540 | because they are some of the most metabolically active cells

01:15:17.720 | in your entire body.

01:15:18.940 | Your photoreceptors are active all the time

01:15:20.940 | as you're looking around,

01:15:21.780 | and even when your eyes are closed, they're active.

01:15:23.840 | In fact, through a weird twist of the biology,

01:15:26.420 | and please look this up if you're really interested in this,

01:15:29.080 | your photoreceptors are actually most active in the dark.

01:15:32.540 | This is so weird.

01:15:33.380 | It's a twist of biology, the way the system's arranged,

01:15:37.060 | that when light comes on, they shut off their activity.

01:15:40.120 | So actually, whether or not you see something in front of you

01:15:42.920 | like this pen or my face is because

01:15:46.220 | the way your photoreceptors are turning off, not turning on,

01:15:49.060 | it's a really cool twist.

01:15:50.240 | And I don't want to go too far down that rabbit hole,

01:15:53.540 | but check it out if you're interested

01:15:55.100 | in how photoreceptors work.

01:15:56.120 | It's absolutely incredible literature.

01:15:59.000 | Just Google, excuse me, look up on the web.

01:16:01.640 | We are not partial just to Google.

01:16:02.980 | I happen to use Google, but use your web browser

01:16:06.020 | to look up a photoreceptors hyperpolarization site,

01:16:10.260 | and you can learn a lot about that

01:16:11.460 | if you're a real nerd for this stuff like I am.

01:16:14.160 | Okay, so red light to the eye can perhaps, it seems,

01:16:19.160 | help maintain vision, doing smooth pursuit exercises,

01:16:22.740 | and accommodation near-far exercises.

01:16:25.340 | Some people suffer from poor eyesight

01:16:27.860 | simply because their eyes get dry.

01:16:29.760 | There are incredible, believe it or not,

01:16:31.940 | lubricating mechanisms for the eye,

01:16:34.380 | not just tears, but thin sheet of oil.

01:16:37.220 | I mean, it's just amazing.

01:16:38.060 | Unless you have some sort of corneal abrasion,

01:16:39.980 | the cornea is the clear stuff on the outside of your eye,

01:16:42.700 | corneal abrasion, when you blink, it's smooth.

01:16:45.960 | You don't feel it.

01:16:47.220 | It's just really, really smooth.

01:16:48.660 | And yet, if you've ever had a corneal scratch,

01:16:50.880 | I've had this, it's really rough.

01:16:52.420 | It is so painful.

01:16:54.060 | You have a ton of pain receptors in the cornea.

01:16:58.800 | The lubrication of the cornea is supported by blinking.

01:17:03.780 | And while it seems a little silly,

01:17:06.060 | some people actually benefit from doing some,

01:17:09.940 | five or 10 or 15 seconds of blinking

01:17:12.380 | and then doing their focused work.

01:17:15.020 | Some people, their eyes are drying out because as we focus,

01:17:17.660 | if we're trying to do something, our eyelids stay open,

01:17:20.500 | the eyes can dry out, but it also can make it such

01:17:23.720 | that when we blink the next time,

01:17:25.380 | there's a kind of a need to focus

01:17:26.900 | because there's some distortions in these oils and liquids

01:17:29.960 | across the corneal surface.

01:17:32.020 | If you're somebody who suffers from dry eye,

01:17:33.640 | I do hope they'll find a treatment or a cure for dry eye

01:17:36.140 | soon, there isn't one at present.

01:17:37.880 | Someone stands to make a lot of money out there

01:17:39.600 | if you can find a cure for dry eye,

01:17:42.060 | let the companies know or start a company.

01:17:44.980 | Right now, it's still a mystery as to how to do that,

01:17:47.100 | but blinking for five to 15 seconds, probably slowly,

01:17:49.820 | not as quickly as I'm doing here on video,

01:17:51.480 | but just maybe a blink every second or two for 15 seconds

01:17:55.120 | can lubricate the eyes and that's not directly related

01:17:58.260 | to anything neural, it's just going to allow the optics

01:18:00.840 | of your eye to be clear, just like when the screen

01:18:02.780 | of your phone gets dirty, like when Costello is texting

01:18:05.060 | on my phone and I pick it up and it's like covered

01:18:06.960 | with smudge to clean it off in order to see things clearly,

01:18:09.580 | the same thing is happening for these optical devices

01:18:12.060 | on the front of your brain, remember, these are brain.

01:18:15.980 | Okay, so a lot of protocols today, almost all of them,

01:18:21.380 | behavioral protocols, I do want to talk a little bit more

01:18:25.280 | about vision and how it works internally

01:18:27.640 | and then I also want to talk about some of the foods

01:18:30.520 | and supplements that have been shown to support vision

01:18:32.880 | and offset visual loss

01:18:34.400 | and maybe even reverse some visual loss.

01:18:36.940 | Let's talk about binocular vision and lazy eye.

01:18:40.100 | I'm very familiar with lazy eye because when I was a kid,

01:18:44.560 | I went swimming one day, one day and I didn't have

01:18:48.240 | my goggles and so something must have been happening

01:18:51.600 | as I recall with the eye moving down through the water,

01:18:54.880 | I've always had this problem that I can only do

01:18:56.620 | the freestyle stroke off to one side,

01:18:58.580 | the people I swim with are always laughing,

01:19:00.240 | somehow I kind of move toward drowning when I try

01:19:02.880 | and breathe on the right side, I think there's some asymmetry

01:19:06.000 | in the way I'm organized, anyway, I was off to my left

01:19:09.780 | and my eye kept going in and out of the water

01:19:12.240 | and there was chlorine in the water

01:19:13.400 | and it was making my eye uncomfortable,

01:19:14.460 | so I just closed my eye, I just decided, you know,

01:19:16.760 | I knew more or less how to swim straight-ish,

01:19:19.840 | might have bounced off the lane lines a few times

01:19:21.640 | but I just used the other eye to kind of steer

01:19:23.240 | for that mark on the wall, got out of the pool,

01:19:26.520 | took a shower, dried off and then completely lost

01:19:30.280 | binocular vision for three days, completely.

01:19:33.240 | The young brain up until about age seven

01:19:37.120 | but maybe even extending out until about age 12

01:19:40.260 | is extremely vulnerable to differences in ocular input

01:19:45.180 | between the two eyes, my scientific great grandparents

01:19:48.340 | won the Nobel Prize for discovering

01:19:50.300 | so-called critical periods, periods of time

01:19:52.220 | in which the brain is more plastic, more able to change,

01:19:55.500 | those two guys, David Hubel and Torsten Wiesel,

01:19:57.900 | thank you David and Torsten, forever changed the face

01:20:00.440 | of visual neuroscience and forever changed the way

01:20:02.820 | we think about treatment of the young brain,

01:20:06.740 | it used to be thought that you wouldn't want to do a surgery

01:20:08.880 | on a young kid because of risk of anesthesia

01:20:12.100 | in young individuals but we now know that you need

01:20:15.020 | to repair these imbalances that even a few hours,

01:20:18.980 | okay, I don't want to scare anybody, I'll talk about reversal

01:20:20.980 | but a few hours of occluding one eye early in life

01:20:24.520 | can lead to permanent, unless something's done,

01:20:27.660 | permanent changes in the way that the brain perceives

01:20:30.260 | the outside world such that when that eye

01:20:32.500 | is opened up again, the brain actually can't make sense

01:20:35.420 | of anything that's coming through it,

01:20:36.380 | it shuts down that visual pathway somehow

01:20:38.580 | so what happened to me was I actually was,

01:20:41.260 | my eye was fine, I got out of the pool, I opened my eye

01:20:43.820 | but I couldn't see through that eye,

01:20:45.420 | everything was blurry, double vision unless I covered

01:20:48.200 | this eye and then I could see perfectly fine.

01:20:50.780 | Fortunately, I went to an ophthalmologist

01:20:53.200 | who understood the literature, thank you Dr. Mark Lurie,

01:20:57.680 | who understood the literature and made it clear

01:21:02.500 | that what I needed to do was to occlude the other eye,

01:21:05.660 | the eye that was working very well,

01:21:07.460 | clearly he understood the work of Hubel and Wiesel,

01:21:09.340 | now again, you don't want to start playing games

01:21:11.180 | with this kind of stuff when you're a kid,

01:21:12.500 | if you wear, let's say you have a Halloween costume

01:21:14.820 | and you wear an eye patch, you're a pirate or something

01:21:17.100 | for Halloween and you cover it up on one side,

01:21:19.840 | probably for the night of Halloween, it's okay,

01:21:21.660 | I do not recommend doing that recreationally

01:21:25.120 | if you don't need that, if you're a young child

01:21:27.180 | or for your child to do that because indeed,

01:21:29.900 | you create imbalances in the brain machinery

01:21:32.420 | that compares information coming in through the two eyes

01:21:34.900 | and it can shut down the neural information

01:21:37.980 | for the occluded, the closed eye.

01:21:40.420 | Now I was able to reverse this issue

01:21:42.220 | but my binocular vision has never been terrific,

01:21:44.220 | I'm much better at the dartboard and still not very good

01:21:47.020 | if I close one eye, I'm much better at the pool table

01:21:49.380 | if I close one eye and I still am terrible.

01:21:52.280 | I was the kid in the outfield,

01:21:55.900 | the ball's coming towards me, the ball's coming towards me,

01:21:57.500 | I'm going to catch the ball

01:21:58.320 | and like a hit me square in the lip.

01:22:00.500 | My binocular vision isn't great

01:22:02.980 | as a consequence of this early event

01:22:05.740 | and I have a hard time with those binocular stereograms,

01:22:09.920 | those images that are kind of,

01:22:11.140 | you're supposed to look at them

01:22:12.200 | and then the binocular depth image like pops out,

01:22:15.480 | all the other kids were going,

01:22:16.900 | there's the whatever, the Statue of Liberty,

01:22:18.620 | there's the American, I see dots, okay?

01:22:21.340 | So I have binocular vision but I use other cues,

01:22:24.580 | I use the near far cues that I talked about before,

01:22:27.400 | motion parallax, the fact that things are closer to me

01:22:29.700 | or moving faster than things further away

01:22:32.000 | in order to judge depth.

01:22:33.740 | And years later when I got involved in,

01:22:35.540 | and I don't suggest this for most people,

01:22:37.580 | I got involved in boxing and martial arts

01:22:40.820 | when I was younger, sometimes we'll see fighters,

01:22:43.440 | this is a slip to avoid getting punched,

01:22:46.060 | it's also generating motion parallax.

01:22:48.140 | Many animals judge depth by moving their head,

01:22:52.660 | not by using other mechanisms of accommodation, okay?

01:22:56.380 | So a lot of birds and monkeys and animals

01:22:59.180 | will judge depth by moving their head like this

01:23:02.620 | or they'll move from side to side.

01:23:04.520 | Animals that will undulate sometimes

01:23:06.420 | are actually doing a depth measurement

01:23:08.340 | because as you move from side to side,

01:23:10.060 | the brain is able to do the math of depth.

01:23:12.500 | So what does this all mean in terms of protocols?

01:23:14.340 | If you're a young person, do your best

01:23:16.180 | to get really good binocular vision,

01:23:18.540 | not just at level of your phone or your tablet

01:23:20.980 | but also at distance.

01:23:22.060 | You will build strong binocular visual machinery

01:23:25.660 | in the brain and at the level of the eyes

01:23:28.100 | and the eye musculature.

01:23:30.060 | Now, if you're somebody who did have an occlusion,

01:23:32.780 | what's needed is to cover up the other eye

01:23:35.140 | to create an imbalance so that the weak eye,

01:23:37.020 | the so-called lazy eye, sometimes referred to as amblyopia,

01:23:40.380 | that eye has to work harder.

01:23:42.060 | So for me, they patched this other eye and made this eye,

01:23:46.180 | eventually I got vision through that eye back,

01:23:47.740 | then they opened them both up.

01:23:49.100 | Now, you might ask,

01:23:50.820 | what happens if you cover both eyes early in life?

01:23:53.300 | And this is where it gets interesting.

01:23:54.680 | You might think, well, if covering one eye

01:23:56.240 | leads to poor vision for that eye after that eye is open,

01:24:00.380 | covering both eyes will probably make you blind, right?

01:24:03.080 | Actually, that's not what happens.

01:24:05.100 | What Hubel and Wiesel discovered and what's been affirmed

01:24:08.300 | many, many more times over in subsequent studies

01:24:11.500 | is that it's competitive, that the two eyes are competing

01:24:14.900 | for real estate up in the brain.

01:24:16.460 | So if you actually cover both eyes,

01:24:18.740 | you actually extend the period of critical plasticity.

01:24:23.060 | This is a really interesting aspect

01:24:24.660 | that other people are starting to leverage now

01:24:26.860 | in terms of how to reopen plasticity later in life.

01:24:29.440 | But please don't go around

01:24:31.260 | with your eyes covered for too long.

01:24:33.040 | There are some retreats and stuff where people go into caves

01:24:36.140 | with absolutely no vision, creates hallucinations.

01:24:39.300 | We'll talk about why that is in just a moment.

01:24:41.440 | But here's my suggestion.

01:24:43.100 | Try and get balanced visual input through the two eyes.

01:24:45.460 | Almost everybody has a dominant eye.

01:24:47.760 | It usually doesn't relate to your dominant hand,

01:24:50.280 | although it can.

01:24:51.400 | And so for me, if I cover up my right eye,

01:24:53.900 | I see much less well, much more poorly.

01:24:56.960 | It's a little bit fuzzy and I have to work harder

01:24:59.420 | in order to see the camera, for instance,

01:25:01.540 | than if I cover up my left eye,

01:25:03.220 | it's actually really easy for me to relax.

01:25:04.860 | I have a dominant eye.

01:25:06.900 | Yeah, you can balance that out

01:25:08.200 | by covering up the dominant eye a little bit each day.

01:25:10.900 | But I would warn any young people, meaning 12 or younger,

01:25:15.900 | against creating these imbalances

01:25:18.080 | if there isn't a clinical need to do that.

01:25:20.320 | And if you do have strong imbalances between the two eyes,

01:25:23.700 | which can be caused by cataract and lens issues,

01:25:27.500 | can be caused by neuromuscular issues, et cetera,

01:25:29.900 | to try and get those dealt with as early as possible

01:25:32.700 | by contacting a really good ophthalmologist

01:25:35.380 | and ideally a neuro-ophthalmologist.

01:25:37.660 | It is very normal.

01:25:39.180 | I should say it's very common for young children,

01:25:42.100 | babies to have an eye that, with strabismus,

01:25:45.340 | that either deviates out or that deviates in.

01:25:47.980 | It is important to correct that.

01:25:50.140 | If you would like to have balanced vision

01:25:53.180 | between the two eyes and for the brain to respond

01:25:56.140 | equally to the two eyes and to have,

01:25:59.180 | I would say, high-fidelity quality vision.

01:26:01.460 | Although some people who have an eye that drifts

01:26:03.860 | can function normally in life,

01:26:06.580 | you have an opportunity early in life to rescue that.

01:26:09.180 | I won't do, well, maybe I will do this,

01:26:11.700 | but I can actually relax this eye.

01:26:14.500 | It's so weak in some cases

01:26:16.120 | that it actually can start to deviate.

01:26:17.460 | Here, I'll just do this here.

01:26:18.380 | It's not crossing my eyes.

01:26:19.220 | So I actually can move, I can misalign my eyes

01:26:22.260 | because I have to fight very hard

01:26:23.940 | to have the musculature for this eye,

01:26:26.580 | keep that eye aligned with the other eye.

01:26:28.700 | And that's because I've been doing eye exercises

01:26:30.920 | since I was in my 20s

01:26:32.340 | 'cause I noticed when I would study a lot,

01:26:34.220 | this eye would start to drift in.

01:26:35.300 | I'd start to see double in.

01:26:36.460 | And then next thing you know, I was just covering the eye up.

01:26:38.600 | It was getting weaker and weaker,

01:26:39.900 | just like the atrophy of a muscle.

01:26:41.780 | So I went to the doctor.

01:26:43.100 | What did they do?

01:26:43.920 | They did the exact wrong thing.

01:26:45.620 | The optometrist I went to gave me a prism,

01:26:47.820 | which adjusted it so that I could see things normally,

01:26:50.020 | which just made the eye weaker and weaker.

01:26:51.780 | It's like putting a weak arm into a sling.

01:26:54.600 | So I had to spend at least three years of 10 minutes a day,

01:26:58.720 | that's what I recommend,

01:26:59.800 | doing near far, covering up my good eye,

01:27:03.940 | doing near far with my bad eye.

01:27:05.880 | And now it's been about 10, 12 years

01:27:09.360 | that I have pretty decent binocular vision.

01:27:12.440 | Now, many of you aren't dealing with this

01:27:14.400 | or have these early childhood issues.

01:27:17.440 | Some of you might be experiencing challenges

01:27:20.240 | with fatigued eyes or with differences

01:27:23.060 | in focus with the two eyes.

01:27:24.260 | These eye exercises of near far smooth pursuit

01:27:26.860 | and checking for dominant and non-dominant eye

01:27:29.960 | can be very beneficial.

01:27:31.700 | Again, I'm not a clinician,

01:27:32.820 | so I don't want to give you protocols

01:27:35.740 | or enforce protocols on anybody.

01:27:37.380 | You need to figure out what's right and safe for you,

01:27:39.340 | giving your vision history.

01:27:42.060 | I do recommend talking to a really good ophthalmologist

01:27:44.340 | if you have severe vision problems of any kind,

01:27:46.640 | or if you want to offset vision problems of any kind.

01:27:49.760 | An optometrist as well,

01:27:51.160 | but ideally it would be a neuro-ophthalmologist.

01:27:53.940 | Okay, I did mention hallucinations

01:27:56.560 | and they're fun to talk about and think about.

01:27:59.000 | For years, people have asked,

01:28:00.460 | why do people get visual hallucinations?

01:28:03.280 | Costello's in sleep right now.

01:28:04.600 | You can probably hear him snoring, he's snoring so loud.

01:28:06.680 | He's probably having hallucinations about rabbits, pizza,

01:28:09.800 | and those are mainly his favorite, and sleep.

01:28:12.400 | He's dreaming about sleep in sleep.

01:28:14.360 | Hallucinations are a property of the visual system

01:28:18.440 | and it was always thought that hallucinations arise

01:28:21.940 | because of over-activation or activation

01:28:24.280 | of certain aspects of the visual system.

01:28:25.820 | I just briefly want to mention a paper

01:28:27.420 | that was published by my good friend

01:28:28.740 | and phenomenal scientist and physicist for that matter,

01:28:33.040 | Chris Neal, who's up at the University of Oregon in Eugene.

01:28:36.580 | They studied LSD-like compounds

01:28:38.920 | and discovered that hallucinations actually occur

01:28:42.260 | because portions of your brain become underactive.

01:28:46.200 | The visual portions of your brain are understimulated.

01:28:49.020 | This is probably why when people go into these cave retreats,

01:28:52.540 | something I've never done, I don't think I ever will do,

01:28:55.180 | where it's completely black,

01:28:56.760 | pretty soon they start hallucinating.

01:28:58.900 | They start seeing things, even though there's nothing there.

01:29:01.860 | The visual system is desperate to make guesses

01:29:04.880 | about what's out in the world.

01:29:06.020 | It's like the eager beaver of your brain.

01:29:07.520 | It's like, what's out there, what's out there,

01:29:08.620 | what's out there?

01:29:10.220 | Even in low to no vision people, blind people,

01:29:12.940 | their brain is going to be making guesses

01:29:15.540 | about what's out there in the auditory world.

01:29:17.180 | What sounds are there?

01:29:18.300 | What touch sensations are there?

01:29:20.740 | For sighted folks, it's going to be

01:29:23.380 | what's out there in terms of light.

01:29:24.940 | Light is the dominant way.

01:29:26.160 | Vision is the dominant way

01:29:27.180 | that we evaluate the world around us.

01:29:29.220 | So it turns out that hallucinations

01:29:31.740 | are an underactivation of the visual system

01:29:34.220 | and then a compensatory,

01:29:35.580 | a compensation by which the visual system

01:29:37.980 | creates activity and hallucinations.

01:29:41.020 | So if you're in the dark long enough,

01:29:42.640 | you start to hallucinate and see things.

01:29:44.660 | So that's a little note about hallucinations.

01:29:47.680 | One of the things that you can do to improve your vision,

01:29:49.860 | and it's also kind of fun,

01:29:51.500 | is to put a Snellen chart in your home.

01:29:54.980 | A Snellen chart is that list of letters.

01:29:57.240 | If you go to the dreaded Department of Motor Vehicles,

01:29:59.840 | actually I'm up for renewal soon,

01:30:01.120 | so I love the Department of Motor Vehicles.

01:30:03.560 | The Department of Motor Vehicles

01:30:04.680 | will have you cover up an eye,

01:30:06.280 | read the letters on the chart.

01:30:09.420 | The letters, of course, get smaller and smaller.

01:30:11.060 | They're trying to figure out roughly what your vision is.

01:30:13.600 | Cover up the other eye, you'll do that.

01:30:16.480 | Some people, including nerdy vision scientists like me,

01:30:19.580 | have had Snellen charts in their office

01:30:22.020 | or in their home for many years now,

01:30:24.240 | and you can just practice,

01:30:25.220 | and you can see how you're doing

01:30:26.240 | sitting at a particular distance.

01:30:27.900 | This is something that's not often mentioned,

01:30:31.200 | but your performance on the Snellen chart will vary

01:30:34.540 | depending on time of day,

01:30:36.140 | because your level of fatigue

01:30:37.980 | and your ability to control that accommodation

01:30:39.900 | and other mechanisms of the eye muscles will vary.

01:30:42.520 | So you can take it as an average.

01:30:44.540 | It's also a good thing

01:30:46.380 | if you're going to get your vision tested

01:30:48.100 | for corrective lenses,

01:30:49.640 | or maybe you're going to do laser surgery

01:30:51.520 | or something of that sort,

01:30:52.540 | if you're thinking about any of that,

01:30:53.780 | to really get it measured by a professional.

01:30:55.620 | The ones that you get in those supermarkets

01:30:57.820 | or in many eyeglass stores,

01:31:00.980 | apologies to the eyeglass stores,

01:31:02.220 | are often wrong by an order of magnitude.

01:31:05.420 | And then when you start putting corrective lenses on

01:31:08.900 | that are over-correcting or under-correcting,

01:31:12.340 | but more often are over-correcting,

01:31:14.340 | then you're essentially weakening the system.

01:31:16.180 | It's like putting a prosthetic on a limb

01:31:17.860 | that you didn't necessarily need or a robot arm

01:31:21.220 | when you didn't need the use of the robot arm.

01:31:23.620 | Although now there's so much excitement about robots,

01:31:25.720 | I think people are going to be doing that.

01:31:26.780 | Anyway, nonetheless, get your vision tested

01:31:30.060 | by somebody who really understands vision,

01:31:32.100 | like an ophthalmologist or a really good optometrist.

01:31:34.740 | If you put a Snellen chart in your home,

01:31:38.860 | you can do that as part of your visual training.

01:31:41.380 | Now, this might seem excessively nerdy,

01:31:43.380 | but what is more important than your eyesight, right?

01:31:46.760 | Eyesight is so vital.

01:31:48.020 | It's right up there with movement

01:31:49.420 | and our ability to move, to generate,

01:31:51.340 | to get up out of chairs and to walk and to run

01:31:53.360 | and to take care of ourselves.

01:31:55.240 | Eyesight and movement are the main ways

01:31:57.860 | that we are able to take care of ourselves

01:32:00.620 | and take care of others.

01:32:01.780 | When you start having compromised eyesight

01:32:03.980 | or compromised movement, people need to take care of us

01:32:06.660 | and we become much more challenged

01:32:08.700 | in moving through our daily life.

01:32:10.320 | So while it might seem nerdy

01:32:11.360 | to have a Snellen chart in your home

01:32:13.440 | or to do a smooth pursuit exercise a couple of times a week

01:32:16.520 | or to get outside for a few hours a day

01:32:18.100 | and do your reading or your laptop work there,

01:32:20.800 | preserving your eyesight and preserving your vision

01:32:23.220 | is one of the most life enhancing

01:32:25.640 | or quality of life enhancing things that you can do.

01:32:27.920 | And if you're a young person

01:32:29.580 | and you can build some of this into your framework

01:32:32.820 | of exercise or brain training, if you want to call it that,

01:32:36.300 | that can be immensely beneficial

01:32:37.560 | and will really set you up to have really good vision

01:32:39.900 | over a long period of time.

01:32:41.240 | Now, of course, there are genetic factors

01:32:42.940 | and there are injury related factors

01:32:45.300 | that can compromise eyesight and our ability to see.

01:32:48.500 | And of course, the things I'm talking about today

01:32:51.620 | aren't going to solve all those issues,

01:32:53.500 | but they can have a tremendous positive impact

01:32:57.000 | if you're willing to do just a little bit of work

01:32:58.900 | and none of this is involving any cost, right?

01:33:02.660 | It's just time cost.

01:33:04.320 | So I do want to talk about a few other things

01:33:06.840 | that can perhaps improve vision.

01:33:09.360 | I want to dispel a few myths about stuff to take

01:33:12.340 | to improve vision.

01:33:13.540 | And then I want to just close

01:33:15.780 | by talking about how we perceive time using our vision,

01:33:19.800 | because that will nicely set the stage

01:33:21.460 | for what we're going to talk about next episode.

01:33:23.980 | So now you understand a lot about the biology of vision.

01:33:27.560 | You understand that light has to arrive at the retina

01:33:29.540 | and get converted into electrical signals.

01:33:32.020 | That process requires things like vitamin A,

01:33:36.420 | a fat soluble vitamin.

01:33:38.540 | It requires things like the carotenoids.

01:33:42.060 | That metabolic cascade, the biochemical cascade

01:33:45.440 | is essential for vision.

01:33:47.820 | And this is why you've been told

01:33:49.220 | that carrots help you see better

01:33:50.900 | 'cause they're high in vitamin A.

01:33:52.500 | There are a few simple things you can do

01:33:55.340 | to support your vision.

01:33:56.820 | First of all, it is true that eating vegetables,

01:34:01.820 | the dark leafy vegetables and things like carrots

01:34:05.060 | that have vitamin A in abundance

01:34:08.020 | and eating them in close to their raw form,

01:34:11.160 | so naturally occurring foods that contain a lot of vitamin A

01:34:14.740 | in their raw form can help support vision.

01:34:19.420 | Now, does that mean that if you ingest

01:34:21.400 | super physiological amounts of that stuff

01:34:23.540 | that it's going to make your vision that much better?

01:34:25.800 | No, but you do need a threshold level of vitamin A

01:34:29.580 | in order to see and in order to see well.

01:34:33.740 | Now, there's a lot of excitement nowadays

01:34:36.560 | about supplementation to help support

01:34:39.300 | the health of the visual system.

01:34:40.740 | And I'm somebody who's pretty open

01:34:43.060 | to novel forms of supplementation.

01:34:45.180 | You've probably gathered that

01:34:46.220 | if you've been listening to this podcast for a while.

01:34:48.800 | You have to determine what's safe and economical

01:34:51.760 | and right for you, what your risk tolerance is, et cetera.

01:34:55.660 | But I want to talk about a molecule

01:34:58.620 | that's in a lot of supplements to support vision.

01:35:01.700 | And there are some really good data on and that's lutein.

01:35:05.900 | Now, the study I want to describe

01:35:07.600 | is actually published in 2016.

01:35:11.300 | It's from the Journal of Ophthalmology.

01:35:12.980 | It's a good journal.

01:35:15.060 | And the title of this paper might catch your attention.

01:35:18.360 | It's increased macular pigment optical density.

01:35:22.020 | That just means that the macula

01:35:24.080 | is an area of the eye for central vision,

01:35:26.900 | for high acuity vision.

01:35:28.080 | Pigment density there is good.

01:35:31.180 | You want pigment there.

01:35:32.860 | Increased macular pigment optical density.

01:35:35.760 | And visual acuity.

01:35:36.980 | Visual acuity is your ability to see things in fine detail.

01:35:40.420 | Following consumption of a buttermilk drink

01:35:43.060 | containing lutein enriched egg yolks.

01:35:45.680 | Remember raw foods?

01:35:47.460 | Lutein enriched egg yolks.

01:35:49.160 | Sounds like a Rocky movie

01:35:50.420 | where he would drink the raw egg yolks.

01:35:52.820 | A randomized double blind placebo controlled trial.

01:35:56.160 | Now I'm not suggesting you go out and eat raw egg yolks.

01:35:59.460 | There's the risk of salmonella.

01:36:00.580 | Although I did hear this.

01:36:01.740 | Someone correct me if I'm wrong,

01:36:02.740 | but the salmonella is actually on the outside of the egg,

01:36:06.040 | not actually in the egg itself.

01:36:07.680 | It's on the shell for reasons that relate

01:36:10.860 | to how that egg got into the world.

01:36:13.280 | That's where the salmonella lives.

01:36:15.120 | But I could be wrong about that.

01:36:17.300 | But raw egg yolks are not something

01:36:19.700 | that most people want to consume.

01:36:21.920 | What is this lutein stuff?

01:36:23.240 | Well, lutein is in the pathway that relates to vitamin A

01:36:27.540 | and the formation of the opsin, the photopigment,

01:36:31.920 | that captures light in the back of your eye,

01:36:33.820 | literally absorbs light, pigment in your eye,

01:36:37.460 | and converts that into electrical signals

01:36:39.300 | and allows you to see.

01:36:40.680 | And there is some evidence.

01:36:42.340 | I spoke to our chair of ophthalmology.

01:36:44.320 | There is some evidence through quality peer reviewed studies

01:36:48.080 | that supplementing with lutein can help offset

01:36:53.080 | some of the detrimental effects

01:36:56.260 | of age-related macular degeneration.

01:36:58.760 | But, I want to emphasize but, or emphasize however,

01:37:03.100 | only for individuals with moderate

01:37:07.100 | to severe macular degeneration.

01:37:09.520 | For people that have normal vision

01:37:11.600 | or with just a low degree of macular degeneration,

01:37:16.600 | these studies did not see a significant improvement

01:37:19.300 | of vision from supplementing with lutein.

01:37:21.980 | So I'm not going to tell you to supplement with lutein

01:37:23.960 | or not.

01:37:24.800 | I don't think any study is holy,

01:37:28.000 | but it does seem that if you have moderate

01:37:30.620 | to severe macular degeneration,

01:37:32.600 | talk to your physician, of course,

01:37:33.800 | talk to your ophthalmologist.

01:37:35.140 | I'll always say that and I'll say it three times.

01:37:37.540 | Supplementing with lutein could perhaps support vision

01:37:42.960 | and offset some vision loss in that case.

01:37:45.000 | Probably also talk to your ophthalmologist

01:37:46.960 | or consider the red light therapy

01:37:48.280 | that I talked about earlier.

01:37:49.720 | Whereas if you have normal vision

01:37:51.920 | or a low amount of macular degeneration,

01:37:55.500 | it does not seem, at least from these studies,

01:37:57.480 | that lutein can have much of an effect.

01:37:59.720 | Now I know and I confess I'm sort of of the mind

01:38:03.820 | that if I personally had age-related macular degeneration

01:38:08.820 | or a propensity for it in my family,

01:38:10.680 | which fortunately I don't,

01:38:11.920 | but in that case, I would think that supplementing

01:38:16.560 | with lutein, provided it's safe,

01:38:18.880 | could perhaps be of benefit

01:38:20.520 | and you might want to consider a low dose of that.

01:38:22.440 | So again, I'm not pushing any of this on anybody

01:38:25.040 | by any means, but you should know

01:38:27.160 | that under certain conditions

01:38:29.000 | of severe macular degeneration

01:38:30.460 | or moderate macular degeneration,

01:38:31.800 | it does seem like lutein can be beneficial.

01:38:33.400 | It does not have to be consumed through raw egg yolks,

01:38:36.040 | although that is the highest density source.

01:38:39.880 | Cooking your eggs, if you like your scrambled eggs dry

01:38:43.440 | or you like your eggs not easy over or whatever, not runny,

01:38:48.360 | then you aren't going to get the benefits of the leucine.

01:38:51.000 | There are other sources of leucine,

01:38:52.360 | non-animal sources of leucine as well.

01:38:53.880 | You can look those up on the internet.

01:38:56.980 | Now, there are other compounds that have been shown

01:39:00.800 | to perhaps be important for offsetting

01:39:03.000 | or helping different forms of vision loss.

01:39:06.440 | One is, I'm going to spell this out,

01:39:08.400 | I-D-E-B-E-N-O-N-E, indebenone, indebenone, indebenone.

01:39:13.400 | I can never pronounce these compounds, forgive me,

01:39:17.400 | unless I've worked with them.

01:39:20.440 | There is evidence that it can be beneficial

01:39:22.600 | for Leber's congenital eye disease.

01:39:27.520 | I would definitely go onto examine.com,

01:39:29.980 | put in I-D-E-B-E-N-O-N-E,

01:39:32.700 | and for things like Leber's optic neuropathies,

01:39:36.560 | which is a degenerative condition of the eye.

01:39:39.660 | Whether or not people should just be taking this stuff anyway

01:39:42.100 | is still an open question.

01:39:43.220 | There aren't a lot of studies about it.

01:39:45.260 | A lot of people that are interested in taking things

01:39:47.460 | to support their vision are taking leucine

01:39:50.460 | as a preventative measure.

01:39:53.020 | I don't pass any judgment one way or the other.

01:39:55.360 | Typically, those supplements also include the zeaxathins

01:40:00.360 | and the astaxyns.

01:40:02.520 | Okay, the pronunciation of this is terrible, I'm sure,

01:40:05.640 | but that's not too far off.

01:40:07.020 | But basically, Z-E-A-X-A-N-T-H-I-N.

01:40:12.020 | Let's see why it's hard to pronounce.

01:40:13.840 | Z-E-A-X-A-N-T-H-I-N, and the other one is A-S-T-A-X-A-N-T-H-I-N.

01:40:18.840 | Both of these have been shown, excuse me,

01:40:23.840 | both of these have been shown to offset

01:40:27.740 | some of the disruption in vision that occurs with aging.

01:40:32.740 | What is astaxaxthin?

01:40:35.320 | It's a really interesting compound.

01:40:37.420 | It's the red pink pigment found in various seafoods.

01:40:41.120 | So shrimp, I'm not a big seafood fan,

01:40:43.880 | but like certain fish, like you'll see at the fish market,

01:40:47.180 | will have that red pink pigment,

01:40:49.480 | and it's also in the feathers of flamingos.

01:40:51.740 | Please don't eat the feathers of flamingos,

01:40:54.240 | and please also don't eat flamingos.

01:40:56.320 | It's structurally similar to beta carotene,

01:40:59.520 | so it's very pro vitamin A,

01:41:02.000 | but it has some chemical differences

01:41:03.680 | which may make it safer than vitamin A.

01:41:05.860 | Remember, vitamin A is a lipid-soluble vitamin,

01:41:09.180 | so it can be stored in our body for long periods of time.

01:41:12.680 | What is the deal with this astaxaxthin?

01:41:15.520 | What are its drawbacks?

01:41:16.440 | Well, we can go to our ever-favorite examine.com.

01:41:20.760 | What does it do?

01:41:21.600 | Well, it has a number of different effects,

01:41:23.400 | a huge number, in fact,

01:41:24.380 | but it does seem to notably increase,

01:41:27.800 | it's now been shown in three studies,

01:41:29.600 | the antioxidant enzyme profile.

01:41:32.800 | It has a number of different effects,

01:41:34.820 | but the most notable for sake of this episode

01:41:36.780 | is the one on ocular blood flow.

01:41:39.140 | It does seem to increase the amount of ocular blood flow,

01:41:41.900 | so the blood supply to the eyes,

01:41:43.680 | so that makes it an interesting compound.

01:41:46.080 | Has a number of other effects for whatever reason.

01:41:49.820 | It also has a notable effect,

01:41:51.760 | several studies have shown this,

01:41:53.720 | on fertility in males,

01:41:55.560 | so it seems to at least double the pregnancy rate

01:41:59.600 | when men take astaxaxanthin

01:42:02.340 | and works, in particular, it seems here,

01:42:06.880 | in men that were previously infertile.

01:42:08.600 | So I don't know if that has something to do

01:42:11.240 | with the blood flow to the eyes, probably not.

01:42:13.360 | It probably has something to do

01:42:14.200 | with something unrelated to the eyes.

01:42:16.620 | Nonetheless, that's an effect of this molecule.

01:42:19.100 | It's also been shown to have positive effects

01:42:21.800 | on things like skin elasticity, skin moisture,

01:42:24.280 | skin quality, et cetera,

01:42:25.800 | probably due to its effects on blood flow.

01:42:28.760 | So lutein, astaxanthin, A-S-T-A-X-A-N-T-H-I-N,

01:42:33.760 | and for people who have concerns

01:42:37.340 | about Leber's optic neuropathies,

01:42:39.400 | which is going to be a small percentage of people out there,

01:42:41.720 | but that is a pretty severe condition,

01:42:44.080 | there are supplements that are available out there.

01:42:46.960 | I do encourage you, as always,

01:42:48.200 | to talk to your ophthalmologist and physician about them.

01:42:51.580 | And I will say that there are a number of people

01:42:53.600 | that take lutein and some of these other things

01:42:56.120 | as a precautionary measure in order to bolster their health,

01:42:59.240 | in the same way that some people take vitamins and minerals

01:43:01.520 | to bolster their health,

01:43:02.360 | and some people are very, health, excuse me,

01:43:04.260 | and some people are very averse

01:43:05.880 | to taking vitamins and minerals

01:43:07.080 | 'cause they feel like they can get all that

01:43:08.640 | from healthy whole foods.

01:43:10.080 | And of course, you can get these things from whole foods.

01:43:13.840 | The question is whether or not you can get them

01:43:15.160 | in concentrations that are sufficient.

01:43:17.280 | I do think that in the years to come,

01:43:19.200 | we are going to see more about lutein.

01:43:22.720 | I think we are going to see more

01:43:24.240 | about some of these other compounds like acetaxaxone,

01:43:28.280 | and hopefully by then I'll be able to pronounce it.

01:43:30.760 | But at present, these things are more or less

01:43:34.160 | in the kind of experimental or self-experimental phase.

01:43:36.920 | There are some good double-blind placebo-controlled studies

01:43:39.200 | like the egg yolk buttermilk study of all things,

01:43:41.840 | published in really good journals.

01:43:43.480 | Journal of ophthalmology, journal investigative ophthalmology

01:43:47.920 | and vision sciences, these are good journals.

01:43:50.400 | These are journals that are peer-reviewed by experts.

01:43:53.360 | The study that I mentioned earlier about keeping rooms dark,

01:43:57.920 | that was also published in an excellent journal.

01:43:59.880 | I think it was JAMA, I'll go back and look.

01:44:01.920 | It's not on my screen any longer, but very easy to find.

01:44:04.880 | And there've been some follow-up studies as well

01:44:06.420 | from the University of Pennsylvania and other universities.

01:44:09.600 | So everything I've talked about today relates to studies

01:44:13.000 | that were done and published in quality peer-reviewed

01:44:15.520 | journals, that doesn't necessarily mean you want to run out

01:44:17.800 | and start taking the stuff that I've described,

01:44:19.920 | or even doing the protocols I've described.

01:44:21.640 | I've given you an array, a pallet, a buffet, if you will,

01:44:24.640 | of things that you could do to try and enhance

01:44:26.720 | or support your vision, depending on how good your vision

01:44:29.840 | is, your family history of vision and vision loss,

01:44:33.320 | your occupational hazards.

01:44:35.320 | People that work with metal filings that are flying

01:44:38.600 | out of machines are going to have a higher degree

01:44:41.480 | of risk to their visual system than will people

01:44:46.080 | who just do office work.

01:44:47.080 | Although if you're doing a lot of office work,

01:44:48.960 | chances are you're not getting a lot of long view vision,

01:44:51.660 | your accommodation mechanisms are going to start

01:44:53.480 | to suffer over time.

01:44:54.480 | I think we can reliably predict that.

01:44:56.640 | So I've tried to give you an array of behavioral tools

01:44:59.520 | and we did touch upon some supplementation tools.

01:45:03.080 | I'd be remiss if I didn't say that because blood flow

01:45:06.040 | is so critical for the neurons of the eye,

01:45:08.120 | remember these are the most metabolically active cells

01:45:10.120 | in your entire body, the cells within your retina,

01:45:12.760 | because blood flow is required to get them the energy

01:45:15.080 | and nutrients they need.

01:45:16.240 | Having a healthy cardiovascular system, right?

01:45:19.360 | Doing endurance work, doing strength training work

01:45:22.440 | regularly is going to support your eyes and your brain

01:45:25.780 | and your vision.

01:45:26.620 | It's indirect, but it's essential, right?

01:45:28.860 | It's necessary, but it's not going to be sufficient.

01:45:31.740 | You're going to have to do other things to support

01:45:33.560 | your eyesight as well.

01:45:34.860 | But having a healthy cardiovascular system

01:45:36.720 | because it's going to deliver blood and oxygen

01:45:39.420 | and nutrients to this incredible apparati

01:45:42.500 | on the front of your face, these two pieces of brain,

01:45:45.900 | is going to support your overall brain health

01:45:48.420 | and vision over time.

01:45:50.080 | So early in the podcast, I talked about how the optimal

01:45:52.700 | window for learning is 90 minutes.

01:45:54.680 | That's the so-called ultradian cycle for learning.

01:45:57.440 | That's why we held our episodes to about 90 minutes.

01:45:59.480 | They're now starting to extend into the hour and 50 minute

01:46:02.140 | and two hour mark.

01:46:03.680 | That simply reflects my enthusiasm and excitement

01:46:06.040 | about these topics and my desire to give you

01:46:07.700 | as much information as I possibly can in each episode.

01:46:10.980 | Please remember, you don't have to listen

01:46:12.400 | to the whole episode all at once.

01:46:14.060 | Everything is timestamped.

01:46:15.160 | Everything is captioned in English and Spanish.

01:46:17.940 | The captions take a few days on YouTube.

01:46:20.200 | We apologize for that, but in order to have them done

01:46:22.600 | correctly, it takes a few days after it's posted.

01:46:25.900 | So if you need those captions, please check back

01:46:29.480 | maybe 24 or 48 hours after the episodes are released.

01:46:33.420 | If you're enjoying this podcast and the information,

01:46:36.020 | if you're finding it beneficial,

01:46:37.480 | there are a couple of things that you can do

01:46:38.400 | that are totally zero cost that really help us

01:46:40.860 | and help you get this information going forward.

01:46:44.260 | One is if you don't already subscribe on YouTube,

01:46:46.740 | please do subscribe.

01:46:48.400 | We release episodes every Monday and hopefully soon,

01:46:50.540 | more often than that, shorter episodes as well.

01:46:53.180 | But every Monday we release an episode,

01:46:54.820 | please do subscribe.

01:46:56.780 | If you don't already subscribe on Apple and Spotify,

01:46:59.240 | that's very beneficial, please do that.

01:47:01.720 | That helps us as well.

01:47:03.000 | If you could give us a five-star review on Apple,

01:47:04.900 | if you feel that that's what we deserve

01:47:06.780 | and Apple also gives you the opportunity

01:47:08.660 | to give us comments, feedback about the episodes.

01:47:11.640 | If you have suggestions about episodes,

01:47:13.660 | feedback of any kind,

01:47:15.660 | please put it in the comment section on YouTube.

01:47:19.120 | Routinely throughout the week after the release

01:47:20.960 | of each episode, I cover content in shorter format

01:47:23.580 | and in more depth on Instagram @hubermanlab.

01:47:26.100 | Every episode is also indexed and searchable

01:47:31.860 | in the search function on our website, hubermanlab.com.

01:47:34.820 | That's also where we post links to various studies

01:47:37.820 | and downloadable protocols, all zero cost.

01:47:40.620 | And as I mentioned, you can search for different topics

01:47:42.760 | and it will bring you to the particular episodes

01:47:45.180 | that contain the information on those topics.

01:47:48.020 | If you'd like to support us on Patreon,

01:47:50.500 | we have a Patreon account.

01:47:51.620 | It's patreon.com/andrewhuberman.

01:47:54.780 | There you can support us at any level that you like.

01:47:57.400 | As well, if you'd like to support us,

01:47:59.540 | please check out our sponsors.

01:48:01.020 | The sponsors that we discussed

01:48:02.180 | at the beginning of the podcast are a vital way

01:48:04.380 | to keep the information being distributed

01:48:06.500 | at zero cost to everybody.

01:48:07.980 | We only work with sponsors that we really love

01:48:11.820 | their products and that we really respect the people

01:48:14.020 | that we're working with there.

01:48:15.520 | And of course, there's no obligation to purchase

01:48:18.220 | or to even check out those sponsors.

01:48:19.900 | But if you're in a position to do so,

01:48:21.300 | that really does help us.

01:48:23.040 | Routinely throughout the podcast, we talk about supplements.

01:48:25.520 | There are a lot of supplement companies

01:48:26.780 | and sources of supplements out there.

01:48:28.940 | The one that we work with and that we partnered with

01:48:30.700 | is Thorne, T-H-O-R-N-E,

01:48:33.160 | because Thorne has the highest levels of stringency

01:48:35.340 | in terms of what they say is in their supplements

01:48:38.280 | is actually in their supplements

01:48:39.380 | because it's independently tested and verified,

01:48:41.220 | as well as the amounts that they list on the bottles

01:48:44.200 | actually are matched by what's in the capsules and tablets.

01:48:47.620 | That's a serious problem in the supplement industry.

01:48:49.800 | And Thorne deals with that problem by being very truthful

01:48:52.880 | and very accurate about what's in their supplements

01:48:55.200 | and how much of those things are in there.

01:48:56.820 | If you want to see the supplements that I take,

01:48:58.660 | you can go to thorne, T-H-O-R-N-E,

01:49:00.720 | .com/u/huberman.

01:49:04.340 | There you'll see all the supplements that I take.

01:49:06.580 | You can get 20% off any of those supplements,

01:49:08.820 | as well as 20% off any of the other supplements

01:49:11.300 | that Thorne happens to make

01:49:13.040 | if you happen to navigate into their website

01:49:14.740 | through that portal,

01:49:16.340 | thorne.com/u/huberman.

01:49:19.860 | And last but not least,

01:49:21.260 | I want to thank you for your time and attention today,

01:49:23.380 | your willingness to learn about vision in the visual system

01:49:25.940 | and the various things that you can do

01:49:27.560 | to help support the health and functioning

01:49:29.360 | of your visual system.

01:49:30.780 | And of course, I want to thank you

01:49:31.920 | for your interest in science.

01:49:33.260 | [upbeat music]

01:49:35.840 | (upbeat music)

The Science of Vision, Eye Health & Seeing Better

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