AMA #6: Eye Health, Why We Yawn & Increasing Motivation

Welcome to the Huberman Lab podcast, where we discuss science and science-based tools for everyday life. I'm Andrew Huberman and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. Today is an Ask Me Anything episode or AMA. This is part of our premium subscriber channel. Our premium subscriber channel was started in order to provide support for the standard Huberman Lab podcast, which comes out every Monday and is available at zero cost to everybody on all standard feeds, YouTube, Apple, Spotify, and elsewhere. We also started the premium channel as a way to generate support for exciting research being done at Stanford and elsewhere. Research on human beings that leads to important discoveries that assist mental health, physical health, and performance. I'm also pleased to inform you that for every dollar the Huberman Lab premium channel generates for research studies, the Tiny Foundation has agreed to match that amount. 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And now, without further ado, I will answer your questions and as always, I will strive to be as thorough as possible, as clear as possible, and as concise as possible. The first question is about eye health, in particular, eye health protocols for people that are aging, but eye health protocols for people in general. The question is, "I'm noticing that my vision, both close and far, is deteriorating. What are the best eye exercises, eye health behaviors, supplements, et cetera for the aging eye?" So, the answer I'm about to provide applies to everybody, regardless of age, which is you want to make sure that you view things both close-up and far away across your day. Many, many people nowadays spend a lot of time looking at their smartphone, looking at the computer screen, looking at books and paper. In other words, looking at things somewhere between 9 in away from their face and their eyes maybe 2 and 1/2 ft away from their face and eyes. This is an unprecedented event in human history, as far as we know, because it wasn't until the advent of the smartphone that we've spent so much time looking at screens at close range relative to looking at things at further distances from our face throughout the day. In fact, it should come as no surprise that the incidence of myopia, of nearsightedness, is increasing dramatically around the world, but is increasing particularly fast in children and in young adults and even in adults who are viewing things at very close range. So, 2 and 1/2 ft or less. Now, I am not saying that viewing things at 2 and 1/2 ft or less is bad for your eyes. That is simply not the case. However, if you want your vision to be maintained or even improved, it's going to be very important for you to view things at a distance as well for ideally several hours per day. I realize some people just simply won't accomplish this. In fact, I'd like everyone to just take a moment and do a rough estimation in your head of how much time during your daytime activities you are viewing things at say 2 and 1/2 feet or 3 feet or less. So, a smartphone, computer screen, paper books, etc. versus viewing things that are 4 feet away, 8 feet away. So, maybe conversation across a table with another human being. Remember those? Um some of us are doing that more now that we seem to be emerging from this whole you know, pandemic phase. However, many people are still mostly just viewing things within very close range. And in fact, if you were to ask yourself, how much time do you spend looking at things at the distance of many hundreds of feet or taking a walk where you're not looking at any screen and you're simply letting visual images or the visual imagery rather pass by on your eyes, I think for most of us that number is getting progressively smaller and smaller with each passing year. So, this is an issue because the structure of the eye is such that the lens of the eye can move, but also that the length of the eyeball from front to back is actually impacted by how close or how far you happen to view things during the course of your day, especially during development. There's a classic experiment that I'd like to just briefly describe to you, which has been performed in chickens, it's been performed in mice, it's also been performed on humans where a visual occluder or a visual image, so an occluder is just a you know, a black uh sort of screen or piece of cardboard or an a image, maybe some you know, black and white checks or checkers are placed at a certain distance from the eye either up close or far away and the impact of that on the length of the eyeball and on the structure of the lens and on the quality and acuity of vision is then measured. And to make a long story short, what these studies show is that if during development you or an animal exclusively looks at things that are up close, very close to the eye, and doesn't ever get long-range vision, the eyeball lengthens, and when that happens, the lens, which of course is in the front of the eyeball, which focuses the light onto the back of the eyeball, which is where the so-called neural retina is, where the cells that sense light are, that visual image lands in front of, as opposed to directly on, the light-sensing portion of the eyeball, what we call the neural retina. It lands too close or near the lens, as opposed to on the back of the eyeball. And that's part of the reason what we call the consequence of that, near-sighted, myopia. In farsightedness, the opposite happens. The visual image is actually focused behind the retina. It doesn't land directly on the retina, which is what you want. It's focused too far behind the retina, and that's due to a shortening of the eyeball. So, what I just described actually explains pretty well why kids who look at computer screens or books up close often need glasses. Um you know, when I was growing up, they called this nerd syndrome. Raising my hand for those of you that are listening. I read an awful lot, um but I also spent time outside, fortunately, and running around on the soccer field and looking at things in the distance, and um playing in the neighborhood with my friends. Kids that spend the vast amount of their time looking at things up close, in particular children who do that indoors for most of their waking time, well, those kids develop myopia. This is part of the reason why we have such a um uh an increase of the incidence of myopia nowadays. What's interesting, and I think most people don't realize, is that even as a young adult and adult, and perhaps even as an older adult, an elderly person, looking at things up close too much at the expense of getting some time viewing things at a distance in particular outdoors can be very problematic because it can exacerbate myopia. So the short direct prescription here is to make sure that you're getting at least an hour or so each day, although ideally it would be more, of long viewing. And that could be done by walking outside and avoiding looking at your phone while walking. It doesn't require that you look at a particular object in the distance. Although if you are scanning for and looking for objects in the distance, uh the way that um you might be on a hike or you're looking out toward or off of a a vista or you're looking for someone in the distance, all of that sort of visual scanning behavior is going to be very good for your eye health and for maintaining vision at a distance. If you are somebody who's far-sided and you have trouble seeing things up close, well then you need to ask yourself whether or not you're spending too much time looking at things off in the distance. Although I want to be very clear that near-sightedness and far-sightedness aren't necessarily the consequence of this near-far viewing. There can be independent causes of near-sightedness and far-sightedness. But for many people out there who are spending progressively more and more time just looking at things up close, you can get this lengthening of the eyeball or challenges in the way that the elasticity of the lens is controlled by the musculature in ways that make it hard to maintain sharp crisp vision when you're looking at things at a distance or up close. Okay? So I can't because there are simply no studies to support the idea that you need exactly 2 hours per day of outside long vision at a particular distance and where that you want to cut off or have a threshold of, you know, 4 hours per day of looking at things up close. But we can say with a high degree of confidence that if you want to maintain or enhance your vision at all distances, that for every hour or so that you spend looking at things say a distance of 3 feet away or less, you want to get at least 1 hour per day total. Doesn't have to be all at once. Of looking at things out in the distance or looking at things beyond 3 ft uh relative to the distance from your eye. Okay? So, I think for some people who are already badly myopic, uh this isn't going to remedy that myopia. You're still going to need corrective lenses. But, if you're somebody similar to the person who asked the question that they're quote unquote noticing their vision is deteriorating, really try and balance out the amount of viewing that you're doing at close distance and long distance. And again, I would not obsess about the total numbers. You know, it doesn't have to be 3 hours and 3 hours. Um but, the more time that you can spend at viewing things at variable distance throughout the day, the better off you're going to be in maintaining and perhaps even enhancing your vision somewhat. Now, there's an additional behavioral tool that we can glean from the recent scientific literature exploring myopia, which points to the fact that children who get 2 hours a day or more of time outside in sunlight, right? One of my favorite topics. I know uh many people are probably rolling their eyes right now uh when they hear me say you really want to view morning sunlight, not through window or windshield, don't wear sunglasses for that, try and get as much sunlight as you can in your eyes early in the day, never stare at any light so bright it's painful to look at, etc. We've done a lot of episodes on this. We have a light for health episode. This is in all the sleep episodes. It's just such a basic foundation of circadian rhythm and health that I just keep repeating it. However, there are also large-scale clinical trials involving thousands of subjects that have shown that people, children in particular, who get 2 hours or more of outside time every day have a much lower incidence of myopia. Now, what's really interesting about these studies is that while some of those kids are looking at things further off in the distance than they would if they were indoors on their tablets or screens or with their nose in a book, it does not seem to be the case that they have to be looking at things in the distance in order to see this reduced incidence of myopia. What's probably happening instead is that the particular wavelengths of light that emanate from the sun, that photon energy in particular is triggering the activation of the so-called intrinsically sensitive melanopsin retinal ganglion cells, which we know are important for setting circadian rhythm, for enhancing mood, focus, and alertness during the day, and enhancing the quality and duration of sleep at night. But those melanopsin intrinsically photosensitive ganglion cells are also involved in networks within the eye that relate to blood flow, that relate to the the ciliary body, which is a structure within the eye that controls uh the aperture and movement of some key components within the eye that also relate to the crispness of vision, that is the acuity of vision at both short and long range. So, there are a lot of technical details there. In fact, um I really hope to get uh the great Russ Van Gelder, Dr. Russ Van Gelder, who's the chair of ophthalmology at the University of Washington in Seattle, who is a world expert in this and the various aspects, both molecular and structural, of the ciliary body and the lens, and he's an expert in uveitis, uh a very interesting topic in its own right, to come to onto the podcast and talk more about eye health, and we will do that in the not-too-distant future. Meanwhile, if the first behavioral protocol for enhancing and maintaining eye health is to make sure that you're spending at least some time balancing out the near vision and far vision during the day, it also stands to reason that you want to get outside for at least 2 hours a day, which I know sounds like a lot, in order to prevent myopia if you're a young person and offset the progression of and maybe even reverse some myopia. We don't know yet based on the data, but there's some indication that's possible by getting outside 2 hours a day. And the cool thing is, because many people, including myself, have a lot of work to do and we need to be on our phones quite a lot, or we choose to be on our phones quite a lot. This effect of getting sunlight outdoors during the daytime for 2 hours or more does not seem to require that you stay off your phone or tablet or that you're looking at things far in the distance the entire time. What this means is if you can get outside onto a patio or a deck or you know, an outdoor table if you can, if weather and conditions permit, and do some of your phone time and computer time and reading, etc. outdoors. Now, if you're already making an effort to get outside, hike, play sports, um take walks, etc., that of course counts towards this 2-hour threshold. And I know this sounds like a lot, this 2 hours, and yet for most people, you know, certainly will vary depending on time of year, but I think striving to get on average about 2 hours of outdoor time as much as you can or opening a window, which wouldn't be as good as getting outside, but opening a window and trying to get some natural light exposure to the eye to trigger the activity of these intrinsically photosensitive melanopsin retinal ganglion cells, that's going to be a really good idea in trying to offset and maybe even reverse some vision loss. Now, the other behavioral protocols which have shown to be useful in terms of maintaining or improving vision relate to the musculature around the eye and the control of the movement of the lens and actually the lens of the eye has its own kind of flexibility. It's a really, really interesting structure. Um I'll geek out on this far too long if um if I don't prevent myself from doing so, but the lens is just incredible. The fact that it has a specific structure of proteins like crystallins and things of that sort and that it can um still derive nourishment from blood flow, but does not actually have vasculature within it. So, it's not if you've noticed, I mean, the the lens of your eyes isn't filled with blood vessels and capillaries cuz it needs light to pass through. Super interesting structure. Um I think the only violation of what I just said is the manatee, right? Those big sort of underwater elephant-like creatures that um I think were or are endangered down in Florida. They were getting chopped up by speedboats, but I think now there's some effort to preserve those big gentle giants. The manatee as I recall has a vascularized lens, which is why their eyes look opaque. It looks like they have cataracts. Um, in any case, you're not a manatee. You have no blood vessel supply to to the lens. Keeping that lens clear is vital. Nowadays that you can they can do lens replacement. There's really um, in pretty incredible um, progress in the in the realm of ophthalmology and surgical replacement of the lens or the cornea or other aspects of the eye. But, if you're somebody who is interested in maintaining your vision, you're going to want to maintain the musculature that controls the movement and the change of shape in that lens and the movement of the eyes, which allows you to transition your vision from very sharp when viewing things up close to very sharp when viewing things at a distance. And this is where some of the so-called near-far exercises can be very useful. So, when we did a full-length podcast on eye health and improving eyesight, which I invite you to listen to if you like, talked about two different types of vision exercises that have been shown to be useful for improving vision at the level of acuity that have a lot to do with improving the musculature and the movement of the eyes and the lens. And that's what's called a smooth pursuit task. So, you could go on to YouTube if you like and put smooth pursuit eye task and do this for a few minutes each day if you're trying to keep your vision strong. And what that task involves is, as the name suggests, smoothly tracking a small dot or crosshatch or arrow on the screen, which is very different than the so-called saccade type eye movements that we often make. Saccades are when you dart your eyes to a particular location to look at something then dart it to another location to look at something. Microsaccades are little tiny versions of those that we're doing most all of the time. Believe it or not, when you look at a visual scene or image, if you did not have those little microsaccades, your brain would adapt or would attenuate to whatever you were looking at and the visual image would actually disappear, which really speaks to how important it is that your perceptions change in order to maintain them. This is very similar to where if something is placed on your uh hand, say a finger, you'll notice that change, but then if you leave it there for a short while, you'll forget that it's there because the cells there have adapted out. There's no change. So, your nervous system is largely responding to change. This is also why when you walk into a room and you often notice a novel smell, let's hope it's a good smell, after a few minutes or so, you don't notice the smell anymore because your olfactory system adapted that away. So, a lot of that adaptation is prevented by those little microsaccades and the macrosaccades, the bigger saccades, are really for moving your eyes around to look for things in visual space. Smooth pursuit is a very particular kind of visual behavior that you can do in a smooth pursuit task. Again, zero cost. Costs a little bit of time, I suppose, to do this on YouTube. And most any of them will do. We can provide a link in the show note captions of one that we like or several that we like. But by doing that smooth pursuit task for a bit each day, maybe just a minute or two, you're maintaining the your ability through the musculature of the eye to do smooth pursuit. And of course, you do smooth pursuit when you move about your day, but for people that are trying to offset or reverse vision loss, doing some additional deliberate smooth pursuit exercises can be useful. The other visual exercise that can be very useful is the so-called near-far exercise. So, this is uh best accomplished, I think, by, you know, holding out a a pen or pencil in front of um your eyes, in front of your head, and focusing very intensely through what's called a vergence eye movement where you bring both eyes to the tip of the pen, and then moving that pen closer and closer and closer to your eyes where you get close enough that you actually have to deliberately bring your eyes I'm For those of you listening, this is what I'm doing right now. To the point where it's blurry and you can no longer hold it in sharp, crisp relief. You can't see it sharply, that is. And then you can move it out a little bit distance and kind of play right around that threshold where it's hard to keep it in focus. Now, and then move it back out again and then in. Doing that for even a minute or two, you'll find is a bit of a strain on your eyes, but you can actually build up the musculature and the neuromuscular connections that allow you to do that more efficiently. And that has been shown to improve certain aspects of vision, especially when people are diligent about doing those exercises, not necessarily every day, but let's say 3 days a week or so. They can be very fast. I actually find them kind of fun for reasons that escape me entirely. Um now, how close you can bring that object and still maintain it in sharp focus will vary from person to person based on a number of things. First of all, how healthy and well-performing their neural retina is, whether or not they have myopia or hyperopia, nearsightedness, etc. Whether or not um for instance, uh you're like me and you have a fairly close interpupillary distance, or whether or not you're more wall-eyed and you have your eyes set further apart. All those things will will dictate the exact performance of of that task, but nonetheless, it's a very useful task to do when trying to maintain or improve vision. Now, of course, there are a lot more behavioral tools that one could use to maintain or enhance vision. I'm going to touching on the biggest and I what I consider the most important ones that are most accessible to people without the need for any fancy equipment at all. And if you want to learn more about other behavioral tools that one can use to maintain or enhance vision, please see the episode that we did on eyesight. You can simply go to hubermanlab.com, put into the search function eyesight or vision, and it'll take you right to it. In fact, everything on that website is keyword indexed and will take you to the various episodes and timestamps that you're interested in according to that keyword. Now, the person who asked this question, who by the way is Paige Singer. Thank you, Paige Singer. And the question got a lot of upvotes because apparently there's a lot of interest in this. Understandably so. Asked about nutrition and supplements for maintaining or improving vision. That could be a very lengthy conversation, but let's just summarize it with a few brief points that we know stand based on the clinical and scientific research. We've all heard that carrots are good for your eyes. Well, it's not carrots per se that are good for your eyes. It's vitamin A that's essential for the so-called phototransduction cascade. The phototransduction cascade is the process by which the photoreceptors, which are in the back of the retina, at least if you're a human, they're in the back of the retina, take photons, light energy, and convert it into electrical signals that's then conveyed to the other cells and neurons within the retina and then passed into the brain to create visual percepts. Most people can get enough of this fat-soluble vitamin we call vitamin A by making sure that they eat at least some dark green leafy vegetables and that they do that in their closest to raw form, maybe cooked a little bit, but not overly cooked. There are other sources of vitamin A out there. You can look those up online. Just look for, you know, sources of vitamin A. Most people will be able to get enough vitamin A from their nutrition and won't require it from a supplement, provided that it's not present at excessively high levels in a foundational supplement or vitamin mineral supplement. Getting in some additional vitamin A from a foundational supplement or vitamin mineral supplement is probably not going to be an issue unless you really take in far too much of that vitamin A. It could potentially provide some insurance, but again, I think most people can get enough vitamin A from their diet if they're taking care to eat the foods that contain vitamin A. Green leafy vegetables being one. The other food that's known to be highly enriched in vitamin A is liver. One of my least favorite foods, regardless of what animal that liver comes from. Liver is somewhat of a popular {slash} controversial organ meat uh in the nutrition space for reasons that aren't interesting um for sake of this discussion anyway. Uh I suppose for those of you that like liver, you could eat a little bit of liver every once in a while. It is, you know, rich in a number of things that are beneficial to health, although for you vegans out there, I'm sure you'll want to avoid liver entirely. I avoid liver cuz I just simply don't like the way it tastes. I've maybe once or twice I've tasted liver that was appetizing to me, and it can be okay, but it's just not uh or at least by my read, it can be okay, but it's um not a food that I actively seek out, order, or prepare for myself on a regular basis. Um so, fortunately, there are other sources of vitamin A as well, and again, I just invite you to all um put into a web search, you know, food sources of vitamin A, and figure out how to get your daily dose of vitamin A by taking in foods that you like for you. And then in terms of supplementation of things that can enhance vision, this is a newer area, and frankly, it's an area where most of the data point to some supplements that can potentially be beneficial in certain disease conditions. So, for instance, in fairly progressed age-related macular degeneration. Age-related macular degeneration is fairly common, uh or more common than we would like, we should say. Um and it does appear that supplementing with certain things like lutein, um which is present in eggs or egg yolks in particular, especially egg yolks that aren't overly cooked, or that can be supplemented, can potentially help with some instances of age-related macular degeneration. But the data on this are still emerging. I consulted with our chair of ophthalmology at Stanford about lutein and some of the other things that you'll see out there like zeaxanthin and astaxanthins, and you know, these um xanthines um come from certain fruits like blueberries, and they're present in supplements and things of that sort. And the consensus I got talking to him and talking to some other ophthalmologists are that if you're really aiming to get a healthy diet, you're avoiding cigarette smoking. And by healthy diet, I mean getting sufficient amounts of vitamin A and lutein through food sources. Again, you can look up where those food sources are. Uh egg yolks just being one of them. Well, then chances are you're not going to need to supplement with lutein or the zeaxanthins or the astaxanthins. However, I have heard anecdotal reports from a number of people that they'll start taking a supplement for eye health. There are a number of them out there. We are not as a podcast affiliate with any of those uh eye health supplements, by the way. And people are reporting enhanced vision. Um you know, I receive emails all the time that say, you know, I'm taking this, you know, lutein at 20 mg per day. And there I should mention that the dosage that's been explored in a couple of studies is 10 to 20 mg per day. Again, you could get that from foods. You could go above that if you're, you know, more um cavalier, or you could um go toward the lower end of that 10 to 20 mg per day uh if you are somebody who tries to who's more conservative, I should say. Well, there aren't people out there who are um you know, looking at lutein, they think it's fairly safe, and they're taking higher dosages of lutein, so 20, 30 mg per day. They're also taking supplements that contain zeaxanthins and astaxanthins, and are reporting anecdotally that their vision is enhanced. I don't dispute those claims, um but as of now, there aren't many papers. I could only find about four, three really solid ones, and then a fourth that point to the specific disease instances where supplementing with lutein, zeaxanthin, or astaxanthin can be beneficial for slowing the progression of things like advanced onset age-related macular degeneration, and the degree of offset for uh that macular degeneration was slight. It wasn't enormous, but it was ro- robust enough that it was it warranted reporting in the paper. Or things like Leber's, which is a particular eye disease that impacts a whole different set of systems in the eye. So, basically what I'm trying to say is when it comes to supplements to support eye health, make sure you're getting enough vitamin A from your diet. If you're not, consider supplementation or consider changing your diet somewhat to make sure you can get that lutein and vitamin A. And if you are interested in it and it's within your budget, I don't know of any um evidence that supplementing with additional lutein, zeaxanthin, and astaxanthin can be dangerous at all. So, for those of you that are really interested in um maintaining or improving your vision, that might be an area that you want to explore. I personally am not taking lutein, zeaxanthin, or astaxanthin, at least not at this time. I do take a foundational supplement uh which is my source of vitamin A in addition to my uh food sources. Um but, I don't suffer from vision loss. I do wear readers at night and I have for a long time. I have a little bit of a a muscular weakness in one of my eyes um that originated in childhood. Um so, occasionally if I get very fatigued, one of my eyes will deviate a little bit, a little bit of um almost strabismus. Uh especially if I've been awake for very long periods of time. It tends to recover once I get a good night's sleep. Some of you that have experienced this where you have one eye that might just drift a little bit. I could do this for the camera if you want. Okay, this is weird. I used to do this um to my sister across the table when we were at a friend's houses for dinner. So, I can actually move one of my eyes in like this, which actually just reflects that there's a a muscle, extraocular muscle uh closer to my nose that's rather weak, which allows me to kind of do that. I can't do it so well with the opposite eye. Um anyway, now I need to blink to kind of clear my vision. But, the point is that if you're somebody who has a slightly deviating eye, slightly, often if you go to the ophthalmologist or optometrist, they're going to give you a prism lens, which is going to redirect the image onto that slightly deflected eyeball. One thing you'll really want to discuss with that ophthalmologist or optometrist is whether or not there are exercises that you could do to overcome that issue without the need for a prism. Because what I saw and what many other people see when they put on a prism lens is that indeed it can um line up their vision or their visual perception better, but indeed it can lead to progressive weakening of the muscle further and further, so then that eyeball starts to deviate further and further. And that raises a larger question, which is should we wear corrective lenses? In fact, if you go online, you'll find or hear about these examples of people that stopped wearing their corrective lenses, their glasses or contacts in order to bring their vision back or improve their vision on their own. Now, if your vision is quite impaired, you're going to need corrective lenses or contacts. However, there are a number of people out there who find that if their vision is somewhat impaired, that forcing themselves to view things at a distance, to do smooth pursuit, to do near-far, and to make sure that they're getting adequate nutrition and things of that sort, can all sum to help offset some of the visual impairment that would occur if they were to just pop glasses on their face and and rely on the corrective lenses in order to focus that the light onto the correct area within the eye onto the neural retina. So, I'm not telling people to throw off or or get rid of their corrective lenses and contacts, but you can be overly reliant on these things like a crutch in a way that perhaps you want to do a little bit of work to try and overcome and then maybe work with a weaker prescription. And certainly in the case of prism lenses, what I mentioned before is a real consideration. It's one I'm very familiar with. So, as a last, but I think very important and exciting feature of visual improvement is red light. I talked a little bit about this on the episode of the Huberman Lab Podcast all about light and health. There's some really spectacular, I think, I consider it spectacular, many other people consider it spectacular, research out of University College London. And the work I'm referring to is Glen Jeffery's work. I've known Glen for a long time. These are animal studies and now two human studies exploring how exposure to red light early in the day can offset some of the vision loss related to age-related macular degeneration or simply age-related visual decline. There's a whole mechanism here that's discussed in that episode, but it has to do with the fact that red light and near-infrared light together or maybe even separately, when viewed for even just a minute to 3 minutes once or maybe two or three times per week maximum, can actually reduce the number of what are called reactive oxygen species in the photoreceptors that convert photons into electrical signals the rest of the visual system can understand. So, that's a mouthful. Basically, what they found was for people 40 years or older, if they viewed this red light at a distance of about a foot and a half, although I wouldn't get too specific with this, for a few minutes each week total, they were able to offset some of the vision loss within a particular domain of vision. And I don't have time to go into the details here, but uh cuz I do that in the Light for Health episode, but you have different types of photoreceptors, cones and rods. You have different types of cone photoreceptors that respond to different wavelengths of light, short, medium, and long wavelengths of light, so-called blue, green, and red cones, they're sometimes called. When these people who are 40 years or older viewed red light on a consistent basis early in the day, and it did have to be early in the day. There was a real circadian effect there. There was a offset of some of the vision loss that would normally occur in a particular wavelength of light range that resulted in better visual acuity overall. So, if you're very concerned about your vision or you're into red light therapies, etc., there are a number of different red light devices out there. At some future point, the Huberman Lab Podcast may partner with one of these red light companies. Um so, right now I'm not going to mention any of them in particular. They're prominent online. What you're looking for is a red light unit that provides red light and maybe far and near infrared, excuse me, light as well. So, something in the, you know, 650 to 720-ish nanometer range. So, really you know, it's going to look red or almost invisible to you if it's really, you know, really far into the infrared. And you'll want to view that at a distance about a foot and a half to 2 feet. And you don't want it to be so bright that it's painful to look at, okay? Cuz you don't want to damage your eyes. But that's essentially what they used in the studies from the Jeffrey lab. And they showed um some pretty impressive offset of some of the aspects of vision loss in these people 40 and older. So, that's an area that uh you may want to explore as well. Especially for folks 40 and older. And again, this red light exposure had to be done early in the day. So, hopefully that collection of behavioral tools near far, smooth pursuit, some of the discussion about lutein nutrition, vitamin A supplementation, zeaxanthins, astaxanthins, uh getting 2 hours of light exposure outside sunlight exposure, get outside to do some of your work, and perhaps even deliberate red light exposure for certain people, can be used to offset your concerns and your actual potential vision loss and maybe even improve your vision regardless of what age you are. Everything I described is supported from the peer-review literature. And again, if you want to get the deep dive on mechanism and further information about dosages, please check out the episode on eyesight and improving your eyesight and the light for health episode again at hubermanlab.com. Thank you for joining for the beginning of this Ask Me Anything episode. 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