A recent large-scale study from China adds to the mounting scientific evidence that more time spent outdoors may reduce kids’ risk of myopia (nearsightedness). Chinese researchers found that adding just 40 minutes of outdoor activity to the daily routine of six-year-olds resulted in a reduced incidence rate of myopia over the next three years. The kids who spent more time outside were significantly less likely to develop myopia, according to the authors writing in The Journal of the American Medical Association. The study’s findings are consistent with those of other research, but the investigators did not seek to determine why more outside time is beneficial to vision, and many questions remain.
Some research suggests that brighter outside light affects eye growth in a way that inhibits myopia, and the beneficial effects are more a function of light exposure than playing sports or other activities. Others speculate the effect is related to exercising distance vision, as is common outdoors and in playing sports. Both factors might be important. This research is timely, authorities suggest, because rates of myopia are increasing worldwide, reaching epidemic levels in parts of Asia. Experts say kids should participate in increased outdoor activity, but remind parents that their youngsters need to be protected from harmful ultraviolet rays by wearing UV-blocking sunglasses, hats, and sunscreen when spending time outside in the sun.