Exercises & Nutrition to Support Eye Health

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In Episode #24, I discuss the science of vision and how your eyes convert light energy (photons) into signals the brain can use to perceive images and to control hormone and neurotransmitter release in the brain and body. Because healthy, clear vision is important to everyday well-being and sense of vitality, this newsletter explains key behavioral and other tools to help improve your vision and eye health and reduce age-related vision decline.

Daily Practices for Eye Health

Throughout the day, your eyes have to adjust in many ways in order for you to maintain a crisp, sharp image of the world around you. The lens of the eye is “relaxed” when looking off in the distance, such as when looking towards the horizon. To focus on closer objects, the eye adjusts by thickening the lens to bring these objects into sharp view. When you spend many hours focused on close-up objects (computers, screens, phones), the eye muscles and nerves that control them are working hard. Over time, viewing objects up close for most of the day changes the length of the eyeball. These changes make quickly focusing on different distances — especially far-off ones — more challenging and can exacerbate myopia (nearsightedness).

• To maintain healthy eyes, focus on periodically letting your eyes relaxthroughout the day. If you do a lot of up-close work (computer, reading, etc.), aim for more balance of near and far viewing, and allow your eyes to view far-off distances multiple times throughout the day. Try taking calls or joining a meeting while sitting outside or while walking, or look out a window to the furthest location you can. You don’t need to fixate on one visual location; rather, viewing to multiple distances far away (beyond 3 feet out to infinity) is key.
• Frequently focusing on close-up objects (e.g., computers) can predispose you to tension headaches too. In fact, for every 30-60 minutes of up-close work, allow all your face muscles to relax (including the jaw muscles) for 1-5 minutes or so while viewing things further out in the distance. Even more time viewing things in the distance in this relaxed manner would be better, but most people are simply not able to divorce themselves for more than 1-5 minutes per every waking hour from screens viewed up close. Still, do what you can.
• Headaches and fatigue due to up-close viewing can also be mitigated by “optic flow.” Get outside for a walk, run or bike ride. Don’t read on your phone for more than a glance or so while doing these activities, of course! The panoramic vision and optic flow induced by self-generated movement can reduce anxiety and improve mood. Alas, while exercise is good, optic flow is not the same on a stationary bike or treadmill. Get outside and move as best and as often as you safely can.

The incidence of myopia is rising around the world, particularly in kids and young adults, who spend more time indoors. Wu et al. found that kids who get more than two hours of sunlight daily have lower incidence of myopia. Much of this effect is probably due to far viewing, and yet we also know that sunlight activates specific neurons in the eye called intrinsically photosensitive retinal ganglion cells that indirectly control blood flow and support the ciliary body (which controls the aperture of the eye) to improve eye health. Those mechanisms may explain why getting outside for 2+ hours/day of sunlight can protect from and possibly help reverse myopia.

• Try to get outside for 2+ hours a day, preferably without sunglasses — unless of course your eyes are very sensitive — and NEVER stare at the sun. A brimmed hat is fine if you need it; people vary in their sensitivity to brightness. If you must, take your work outside to reach that 2 hours. You can still focus on a computer, studying or working outside, as the ambient sunlight will aid eye health and contribute positively to overall health. Remember to take visual breaks throughout the day to do far viewing, even if working outside.

Eye Training Exercise

Try the following exercises to help improve voluntary control of these muscles to improve vision, focus eyes quickly to different distances, and offset age-related vision decline:

1. Smooth Pursuit Eye Task – Practice following a small object with your eyes. Try to follow the object with smooth eye movements — not allowing eyes to dart from one point to another.
2. In nature, practice this type of eye movement by watching a bird in flight. Or, during a sports game, try smoothly tracking a tennis ball, golf ball or hockey puck. You can also practice this exercise at your computer.
3. Try to complete this type of exercise for 2-3 minutes, 3x per week.
4. Near-Far Exercises – Accommodation is the eye’s ability to adjust focus to objects near or farther away by changing the optics of the eye and lens itself. As some of you might have already experienced, this ability naturally declines with age, and it takes more time to focus on objects at different distances (e.g., focusing on a server at a restaurant, then looking down to read the menu).
5. Train eye muscles by visually focusing on a pen or other small object positioned about 1.5 feet in front of your eyes. Slowly, move the object closer toward your nose while keeping the object in focus. Continue to move the object closer and closer until the image gets blurry.
6. With practice, your ability to move the object nearer to you while maintaining sharp focus will improve. The effort involved will also be less over time.
7. You can also practice this exercise in reverse: focus on an object near to you, then move it farther away.
8. Improve your control of eye muscles and the associated neural connections by practicing this exercise for around 1-2 minutes every other day.

Set Your Circadian Clock

The eyes are also important for communicating information about the environment to set your body’s circadian clock (sleep-wake and hormone cycles). The melanopsin retinal ganglion cells that reside in the back of the eyes (in the retina) signal the time of day to the brain. This information affects sleep rhythms, mood, alertness, hormones, metabolism, learning/memory, pain thresholds, blood glucose, cortisol and dopamine levels. These cells are maximally activated in response to blue-yellow light contrasts that are present in low solar angle sunlight (i.e., sunlight in the early morning and early evening).

• To maintain circadian rhythm consistency, ensure you get 5-10 minutes of sunlight viewing (minimum) as soon as possible after you wake up. Try to get outside a second time in the late afternoon or early evening to do the same as well. Sunlight early in the morning will prime your body to sleep 12-16 hours later and improve overall energy and mood throughout the day along with regular awake-sleep and other 24-hour rhythms.
• The melanopsin retinal ganglion cells are very sensitive and able to detect even relatively dim light at night. Nighttime activation of these cells can disrupt sleep, reduce melatonin, and reduce next-day dopamine release, and it may exacerbate myopia.
• Try to minimize light in your sleeping environment. If you need to use light, such as when walking to the bathroom, try using a red light. The longer wavelengths of red/orange light do not sufficiently activate the melanopsin cells — unless they are very bright.
• Also, try to wean kids off nightlights and make lights as dim as possible to reduce their chance of developing myopia. Even a small amount of light in the room can alter next-day glucose metabolism.

Nutrition and Supplements for Eye Health

The photoreceptors and associated molecules of the eye can be further supported through a healthy diet:

• Vitamin A is essential for phototransduction (the process of converting light energy into electric signals for the brain). A diet rich in dark, leafy green vegetables (like kale, spinach, romaine lettuce and broccoli) and yellow/orange vegetables & fruits (squash, pumpkin, carrots, mango, cantaloupe) will support sufficient vitamin A intake.
• Additional vitamin A is likely found in most foundational supplements.
• Lutein is another molecule known to support the eye’s phototransduction processes. Foods such as egg yolk and dark, leafy vegetables are rich sources of lutein.
• There is also evidence that lutein supplementation (10-20 mg/day), can reduce moderate to severe age-related macular degeneration.
• By focusing on a diet rich in nonprocessed fruits and vegetables, you will best be able to derive the antioxidant and vitamin support important for overall health, including eye health.

Contact Lens Caution

As a final note, for those who wear contacts, ensure you follow the package information for total length of wear (different for daily vs. monthly lenses), note expiration dates, and do not overuse contacts. Contacts are made of special material to ensure oxygen diffusion into the eye. However, contact overwear, such as wearing contacts for too many hours in a day, sleeping in nonextended-wear contacts, wearing old or expired contacts, or inadequate lens care resulting in dirty lenses, causes inadequate oxygen flow to the eye. If contact overwear continues, blood vessels can start to grow into the eye, and this can result in impairment of the visual field and painful associated health conditions.

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Thank you for your interest in science!

Best wishes,
​Andrew