An article in the March 19 issue of Nature analyzed the worldwide myopia pandemic, specifically suggesting that the situation is particularly serious in East Asian countries such as China, and that the root cause of the current outbreak of myopia in children is the lack of adequate outdoor activities. The prevalence of myopia in China has been increasing rapidly in recent years. 60 years ago, the prevalence of myopia among 20-year-olds in China was only 10% to 20%, but now the prevalence of myopia among 20-year-olds is over 80%. The prevalence of myopia in adults in the United States and Europe is about 50 percent, twice the rate of a century ago. It is estimated that by 2020, about 1/3 of the world’s population of 2.5 billion people will have myopia. Australian myopia experts say we are now entering an era of high myopia prevalence. Myopia is more than just an inconvenience. High myopia increases the risk of retinal detachment, cataracts, glaucoma, and even blindness. Currently, about one in five East Asian college-age people have high myopia, and half of them may develop irreversible vision loss. A portion of myopia in children occurs because of genetic factors, but the majority of myopia in children is due to environmental factors. There is a consensus that the most important environmental factor contributing to myopia is the lack of adequate time spent outdoors. The most important reason for the increasing prevalence of myopia is that children are spending too much time indoors and must be allowed to spend more time outdoors.