This graph shows an increase in the number of short-sighted adolescents in Taiwan over the last 20 years. This number has gone up by around 40 percent for 12-year-olds, but has shot up by about 70 percent for 18-year-olds. Furthermore , this hasn t been a steady increase, as the rate of short-sightedness, or myopia, has rocketed in the last five years compared to the previous 15 years.
There are several hypotheses that may explain these results. One is that teenagers study more than they used to. Too much "near work" can cause eyes to lose the ability to focus on distant objects. Another theory is that smartphones and other electronic gadgets have become more prevalent in the last 15 years, leading to eye muscle strain caused by focusing on small fluorescent screens.
Research has shown that one way to prevent myopia in young people is to ensure they spend more time outdoors. Humans eyes have evolved to process natural light and look at distant objects, so being outdoors doesn t impair our vision in the same way that staring at books and screens does.