Does using a computer for hours in a darkened room hurt teenagers’ eyes?

Probably not, though there’s no hard proof.

“In theory, we do think that the more you use your eye muscles and the visual processes in the brain, the more likely you are to develop nearsightedness, especially at a young age,” said Dr. Sandra Cremers, an ophthalmologist at the Massachusetts Eye and Ear Infirmary. And there are animal studies suggesting this effect does occur. “But when we do randomized controlled studies in people, we don’t find it an issue,” she said. “There is controversy in this area.”