By Nathan Seppa
Rogers Hornsby, one of the best hitters ever to swing a baseball bat, had a reputation for being standoffish. Teammates complained that he didn’t socialize, even balking at attending movies — prime entertainment during the 1920s. Sitting in a dark theater watching a bright screen made it difficult to hit a baseball, Hornsby used to say. Hard to argue with a guy who reportedly had terrific eyesight and who finished three seasons with a batting average better than .400.
![](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2013/01/17078.jpg?resize=300%2C142&ssl=1)
![](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2013/01/17079.gif?resize=300%2C142&ssl=1)
![](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2013/01/17080.gif?resize=300%2C179&ssl=1)
![](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2013/01/17081.gif?resize=300%2C198&ssl=1)
Hornsby might have been onto something that scientists are only now coming to embrace: Too much time spent indoors may contribute to nearsightedness, also called myopia.
Nearsightedness has increased steadily in North America and Europe in recent decades, with one-third of adults in the United States now nearsighted. That figure alone is cause for concern. But the rise of myopia in East Asia is downright alarming. Recent studies of young men in Seoul and college students in Shanghai find that more than 95 percent are nearsighted. Increases also have shown up across other urban centers in the Far East.