SAN DIEGO, CALIF (March #, 2017) - Remember when your mom used to nag you to go outside and play? Turns out she was onto something. New studies show that if you took mom’s advice back when you were a kid, you might be enjoying have better eyesight now as an adult. Why? It has something to do with greater exposure to sunlight during childhood, although researchers still haven’t quite figured out exactly how it all works.
Nearsightedness is incredibly common, affecting an estimated 40 percent of Americans and up to 90 percent of young adults in Asian countries. A 2015 study estimated up to one-third of the world's population may be nearsighted by the end of the decade - that's 2.5 billion people. The following year, an analysis of 145 studies predicted nearly half the world will be nearsighted by the year 2050.
“That’s just an extraordinary number of people, and the big question is, what’s causing this rapid mass-deterioration of vision?” says Sandy T. Feldman MD, Medical Director of Clearview Vision Center in San Diego.
Nearsightedness (myopia) is a vision problem in which close objects appear clear but distant objects are blurry. This condition is caused by refractive errors in the eye, which occur when the shape of the eye prevents light from focusing properly on the retina. This can be caused by changes in the shape of the eye - such as the length of the eyeball or shape of the cornea - and/or changes in the lens due to aging. But what exactly is responsible for these changes?
Two studies, one published in 2007 and another in 2008, found that rates of nearsightedness in children appeared to be closely linked to the amount of time spent outdoors. The greater the number of hours spent playing outside, the lower the risk of nearsightedness.
“This suggests that allowing kids to stay inside too much may be at the heart of this growing problem with nearsightedness,” explains Dr. Feldman. “Young people today now spend less time outside than ever before. They’re inside virtually 24/7, doing homework, playing video games, texting their friends. That’s not a good thing when done to excess, especially if adequate sun exposure is what we need for optimal vision.”
Recently, British researchers investigated the connection between time spent outdoors and vision among the elderly. As reported by The New York Times, the researchers gave vision exams to more than 3,000 older European men and women and took detailed histories of their education, careers and how much time they spent outside at various stages of their lives.
This biographical information was then cross-referenced with historical data about sunlight.
The results? An undeniable correlation between current eyesight and a person’s lifetime exposure to sunlight. Those exposed to the most sun, particularly between the ages of 14 and 19, were about 25 percent less likely to have developed nearsightedness by middle age. An important thing to note - blood tests revealed that the reduction in myopia was not related in any way to vitamin D levels.
“Although there are still a lot of unanswered questions, it’s clear is that the more time children spend outdoors, the lower their risk of nearsightedness,” says Dr. Feldman.
“It’s all a matter of balance, of course. Spending time in the sun on a regular basis, say for one to two hours a day, is good for our eyes and our overall health and well-being. Just be careful not to overdo it.”
About Sandy T. Feldman
Sandy T. Feldman MD is the Medical Director of Clearview Eye & Laser Medical Center in San Diego and has successfully performed more than 20,000 refractive procedures. Her many honors and awards include “Best Laser Eye Center” in the 2016 San Diego’s Best Union-Tribune Readers’ Poll, “Top Doc San Diego” and the Goldline Award, an honor granted to only 10 laser eye care providers in the U.S. each year. She has been profiled in Forbes, Newsweek and other respected publications, and makes regular appearances as an expert resource for media outlets such as The Doctors, e-Heath Radio and various San Diego TV network affiliates. Dr. Feldman is a fellow of the American and European College of Ophthalmic Surgeons and a member of the American Academy of Ophthalmology and the American Society of Cataract and Refractive Surgery. For more information, please visit clearvieweyes.com.
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