How spending time outdoors fights childhood myopia
Sending kids outside to play boosts physical and mental health—and helps them see more clearly, too. Multiple studies show that outdoor play is one of the best ways to prevent or slow the development of myopia, or nearsightedness, a condition affecting more children than ever before.
What is myopia?
Myopia is another term for nearsightedness, or vision that’s only clear at close range. It results from an overly elongated eyeball that focuses light in front of the retina, causing blurry vision.
Over the last few decades, myopia has become a childhood epidemic worldwide. Researchers estimate that around half the world’s population will be myopic by 2050.
Babies are born farsighted, with shorter eyeballs that naturally lengthen as they grow. Normal growth patterns result in a natural shift toward nearsightedness in adulthood—that’s why many adults may “suddenly” need reading glasses in middle age. For most, nearsightedness is more of a mild nuisance than a medical concern.
But when myopia begins in childhood, particularly at very young ages, doctors get more concerned. Myopia tends to progress with age, so a toddler with myopia will likely become progressively more nearsighted each year. Without intervention, these children face increased risk for conditions like glaucoma, retinal detachment, and cataracts in adulthood, says Thao Phuong Le, MD, an ophthalmologist at Eye Associates Northwest, PC in Seattle’s First Hill neighborhood.
Why are more children being affected?
What’s driving the increase in myopia? Some kids can thank their genes; when both parents are nearsighted, a child’s risk of developing myopia nearly triples. But the dramatic increase in myopia can’t be entirely explained by genetics, says Anita Lam, OD, an optometrist at Eye Associates Northwest, PC in Seattle
Increased screen time, longer hours spent on homework, even more time spent reading at younger ages are driving the increase, Lam says. “Kids are spending more time on devices, so they’re focusing at close range for extended periods of time, and that’s driving up rates of myopia in childhood.”
Sitting too close to the television, squinting, frequent headaches, or holding devices and books very close to the face are signs a child might be nearsighted. When a child shows these signs, or if one or both parents are nearsighted, a complete eye examination is in order. Taking a child to a vision provider, instead of waiting for a school vision screening, means kids get a more comprehensive checkup and can begin therapeutic interventions sooner, notes Lam.
But caregivers often don’t see any signs, especially when a child is myopic in just one eye. “In these cases, the child compensates with their other eye, so parents may have no idea their child can’t see normally with both eyes,” says Lam. “Parents can play games like ‘I Spy’ and ask kids to cover one eye to see if they notice any differences in kids’ vision on either side.”
Slowing the trend
Per the American Optometric Association, early diagnosis improves outcomes for myopic kids. Diagnosing some children used to be difficult, because traditional vision exams present problems for very young kids, those who aren’t verbal, or those with special needs, but new eyeball-scanning devices can help spot vision abnormalities in seconds. “Our son had this done at his 3-year wellness check and it showed that something was off. I appreciated how easy it was for him,” says Kira Miller of Tacoma, Washington.
And efforts to slow myopia’s progression can work well, particularly when kids use them consistently, says Lam. Daily atropine eyedrops are a well-researched and widely used (but not FDA-approved treatment) to slow progression. The more concentrated drops used in the past caused skin irritation and sensitivity to light, but research shows that lower-dose .01 percent drops are just as effective with fewer side effects.
Parents can also consider Ortho-K contact lenses, hard lenses worn overnight to reshape the eye and correct myopic vision. Research shows these lenses are safe and effective when used properly, says Lam. “Somewhat like wearing an orthodontic retainer at night, the lenses can be effective when a child wears them consistently.”
But the best way to prevent or slow the development of myopia is also safe, simple, and free: Send kids outside. Research shows that eye doctors recommend more outdoor time more than any other protective intervention for myopia.
“When kids spend time outside, they give their eyes a break from close focus. I recommend ninety minutes of time outside daily, putting devices away around a hour before bedtime, and the 20-minutes on, 20-seconds-off rule: Give eyes a break from reading, homework or screens every 20-minutes,” says Lam.
More research is needed to determine just how time spent outdoors helps protect vision, Lam says. “It may have something to do with exposure to sunlight or vitamin D, but more studies are needed.” For now, the recommendations are clear. We’ll see you outside.
By Malia Jacobson