To the parents of her young patients with myopia (or nearsightedness), Diane Suarez, OD, offers this piece of advice: “Make sure your children get plenty of sunlight.”
Her suggestion concurs with a recent report from the National Academies of Sciences, Engineering and Medicine that recommends children spend up to two hours a day outside, at least one of those hours during the school day.
“We encourage young kids to go outside and get sunlight exposure, because it helps decrease the progression of myopia,” said Suarez, an optometrist at Open Door Family Medical Center in Ossining. “We see kids as young as 6 or 7 with myopia, and if we can slow down the rate even a little bit every year, it will make a huge difference down the line.”
The prevalence of myopia in children has increased dramatically in the United States over the past half- century, from 25% in 1972 to more than 40% today. This mirrors what Suarez sees in her practice at Open Door.
Myopia makes it difficult to see things that are far away. Vision is clear when looking at something up close but blurry when focusing on objects at a distance.
“The most obvious sign your child has myopia is that they have trouble seeing the teacher or the board at the front of the classroom,” Suarez said. Younger children may rub their eyes, sit close to the TV or squint when trying to see something in the distance, she added.
Nearsightedness happens when the axial length of the eyeball (the measure from front to back) is too long. As children grow and their eyes develop, the axial length can become too long, and the cornea (the lens of the eye) can curve too sharply. This combination makes it hard for the eye to focus clearly on distant objects.
The problem with myopia isn’t just that children need to depend on glasses or other corrective lenses. Over the years, myopia can lead to retinal detachments or degeneration and other conditions that can affect your eyesight.
“Managing the rate of progression is super-important,” Suarez said. “Sunlight itself doesn’t stop the myopia, but the idea is to slow down the progression, so maybe it goes up a ¼ diopter instead of ½ or 1 diopter every year.”
Various studies have shown the benefits of sunlight on reducing the progression of myopia in young children. Suarez cites one study in particular: Of more than 700 schoolchildren in Taiwan, researchers found the rate of progression decreased more than 50% with those children who spent considerable time in the sunlight compared to those who did not.
Genetics and environment also play a role in the increase of myopia. If both parents are nearsighted, chances are their children will be, too. Yet, as Suarez has seen, many children are myopic without having myopic parents. This may be due to the increased reliance on “near work,” which is at least partially due to the amount of time children spend on computers and cell phones, playing video games and using social media.
“Myopia may be an adaptive reaction to doing so much near work,” she said. “I tell kids and parents that for every 20 minutes they spend up close, they need to take a 20-second break where they look away to break the cycle. The idea is to relax the accommodation of the eyes and muscles from the near point task.”
There are several theories on the benefits of sunlight – in addition to keeping children away from the time they spend in front of computers and phones. One theory is that children may exercise more when they are outdoors and that exercise is somewhat protective. Another is that more ultraviolet B radiation from the sun makes for more circulating vitamin D, which prevents abnormal childhood eye growth and myopia. Another is that light itself slows abnormal eye growth and that outdoors light is simply brighter.
Still another theory, Suarez said, is that sunlight stimulates the release of the hormone dopamine from the retina, slowing the rate of myopia progression.
“Many of our parents tell us that having their children spend more time outdoors is difficult because they both work and it’s grandparents or caregivers who are with the children during the day after school, or there isn’t a lot of outdoor space nearby,” she said. “I tell them all you need is to have your children walk around the block or play in the courtyard with the grandparent or caregiver. Just take them outside. They need the sunlight.”
