“When you have elongated eyes, the stretched structures inside are at a much higher risk for many ocular health conditions—some of which can permanently reduce vision and, in some cases, cause vision loss and blindness,” says Laura Di Meglio, an instructor of ophthalmology at the Wilmer Ophthalmological Institute at Johns Hopkins University School of Medicine.
Some such worrisome eye conditions include glaucoma, premature cataracts, macular degeneration, and retinal tears and detachments.
Why sunlight is good for eye health
Playing outside and being in the sun improves eye health for everyone, but especially does so for kids. “For younger children whose eyes are still developing, spending time outdoors helps prevent excessive elongation of the eyeball,” says Chase Ludwig, a vitreoretinal surgeon at the Byers Eye Institute at Stanford University School of Medicine.
This is primarily because bright sunlight triggers the release of a neurotransmitter found in the brain and retina called dopamine, which, he says, “regulates eye growth and ensures the retina maintains its proper shape.”
Dopamine also helps the eye adapt to different light conditions by regulating how images interact with specific receptors in the retina, adds Inna Lazar, an optometrist practicing in Darien, Connecticut—an interaction that further improves the shape and health of the eye.
(4 ways to get more ‘nature therapy’ into your kid’s schedule.)
Another benefit of sunlight is that it supports vitamin D production, “which can strengthen ocular tissues,” says Isdin Oke, an ophthalmologist at Boston Children’s Hospital and an instructor of ophthalmology at Harvard Medical School. He says it does this, in part, by reducing eye inflammation, improving corneal function, and helping with tear secretion. Di Meglio adds that vitamin D also strengthens the outer layer of the eye known as the sclera, “which helps prevent stretching or thinning.”
Aside from its effect on nearsightedness, “vitamin D is also thought to play a role in preventing or improving other eye conditions such as age-related macular degeneration, diabetic retinopathy, dry eye disease, and uveitis due to its anti-inflammatory and anti-oxidative properties,” says Jacqueline Nguyen, a clinical assistant professor at the University of Michigan Kellogg Eye Center.
Such reasons are why multiple studies show that regular outdoor exposure is associated with lower rates of myopia in children.
Other factors playing a part in myopia rates
But it’s not just sunlight that keeps your eyes healthy—being outside and away from additional factors that harm your vision can play a role too.
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