Kids Who Spend More Time Outside Have Lower Risk For Nearsightedness

(Reuters Health) – For primary school children in China, spending an extra 45 minutes per day outside in a school activity class may reduce the risk of nearsightedness, or “myopia,” according to a new study.

In some parts of China, 90 percent of high school graduates have nearsightedness, and rates are lower but increasing in Europe and the Middle East, the authors write.

“There were some studies suggesting the protective effect of outdoor time in the development of myopia, but most of this evidence is from cross-sectional studies (survey) data that suggest ‘association’ instead of causality,” said lead author Dr. Mingguang He of Sun Yat-sen University in Guangzhou. “Our study, as a randomized trial, is able to prove causality and also provide the high level of evidence to inform public policy.”

Intense levels of schooling and little time spent outdoors may have contributed to the epidemic rise of nearsightedness in China, he told Reuters Health by email.

The researchers divided 12 primary schools in China into two groups: six schools continued their existing class schedule, while six were assigned to include an additional 40 minutes of outdoor activity at the end of each school day. Parents of children in the second group were also encouraged to engage their children in outdoor activities on the weekends.

In total, almost 2,000 first-graders, with an average age of almost seven years old, were included.

After three years, 30 percent of the outdoor activity group had developed nearsightedness, compared to almost 40 percent of kids in the control group, according to the results in JAMA.

That means kids who spent more time outside were 23 percent less likely to develop nearsightedness, the authors write.

The study doesn’t investigate why time outdoors might protect eyesight, but He said that some experimental work suggests brighter outside light affects eye growth in a —> Read More