Myopia Is Becoming an Epidemic

Children should spend much more time outdoors to prevent myopia, or nearsightedness. Researchers say an epidemic is coming. Here's what parents can do.

Millions of kids around the world are becoming nearsighted, and the cause may simply be a lack of sunlight. 

Nearsightedness, or myopia, is caused by an elongation of the eyeball. When light hits the eye, the lens focuses it in front of the retina, instead of right on the retina. The result is that anything further away than a few feet will appear slightly blurry. 

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In the United States, 41 percent of children ages five to 17 in urban areas are estimated to have myopia. About 16 percent of rural residents that age likely have the condition.

Having a parent with myopia increases a child’s risk. But genes take centuries to change, and myopia diagnoses increased only 25 percent in the early 1970s. Something in the way people live today seems to have made myopia more common.  

“We are going down the path of having a myopia epidemic,” Padmaja Sankaridurg, head of the myopia program at the Brien Holden Vision Institute in Sydney, Australia, told the journal Nature. 

At the current rate of increase, the World Health Organization predicts that half of the world’s population will be nearsighted by 2050. Children with higher degrees of myopia are more likely to develop cataracts, glaucoma, macular degeneration, and retinal detachment later in life. Five to 15 percent of all nearsighted people may have severe cases and even become blind.

Conventional wisdom blames reading, an idea that took hold more than 400 years ago when German astronomer and optics expert Johannes Kepler blamed his nearsightedness on his constant study. That theory led ophthalmologists to recommend headrests to keep students from going through their books too closely. 

But it’s more likely the problem is too little sunlight. That’s why posters in Singapore  once said, “Keep myopia away, go outdoors and play.”

Spending an extra 76 minutes a day outside can lower a child’s risk of myopia by 53 percent, according to one overview. Other research suggests more sunlight can affect the progression of myopia as well.

When you’re outside, your eyes become used to viewing long distances, which has a protective effect. When the eye is exposed to bright light, the retina releases dopamine, which triggers changes. When there isn’t enough light, such as when you’re indoors, that cycle is disrupted, which affects eye development. Bright screens at night could further disrupt the natural cycle that has existed for eons. 

Research suggests that children need at least two hours of outdoor light per day. Lamps used by people with seasonal affective disorder, meanwhile, generally need to emit light at 10,000 lux to approximate sunlight and be effective. 

Researchers are investigating whether such lamps could help prevent myopia. In China, classrooms are experimenting with glass walls for extra light.

Atropine drops, which dilate the pupil, can slow the development of myopia. Typically, your child would take the drops at bedtime.

“What we’re seeing is that for most kids — about 90 percent — their rate of myopia progression decreases or slows by about half. The sooner they start taking it, the less nearsighted they’ll be overall,” says David Epley, MD, a pediatric ophthalmologist in Kirkland, Wash., who is involved in atropine research. Side effects are very rare, but myopic progression increases again if your child stops using the drops.

Another option is a daily disposable special contact lens.

But even with drops and contacts, your child still needs to limit his or her screen time on devices and TV and get daily sunlight, the more the better.

Avoiding glasses or new prescriptions is one goal, but children need outdoor play time for many reasons, such as stress relief, exercise, socializing, and developing motor skills.

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