Despite parental warnings, video games improve vision

Parents who warn teens that they will ruin their eyes playing video games may wish to avoid the current issue of the journal Psychological Science.

In it, researchers from the University of Rochester in New York report that playing action video games for an hour or so daily actually helps sharpen visual acuity.

Specifically, in tests that assess the ability to see objects accurately in a cluttered space, game players scored higher than nonplayers.

"Action-video-game play changes the way our brains process visual information," said Daphne Bavelier, a professor of brain and cognitive sciences at Rochester and lead author of the study.

"After just 30 hours of training, people who didn't normally play video games showed a substantial increase in the spatial resolution of their vision, meaning they could see small, closely packed letters, like those on an eye chart, more clearly, even when other symbols crowded in," she explained.

Researchers stress that playing video games won't have any effect on most of the things that influence a normal person's ability to read an eye chart -- the size of the eye, the shape and thickness of the cornea and lens.

Some visual deficits are not really optical in nature, but instead are the result of dysfunction in optical nerves and the brain.

"It is our hope that video-game training can help these people," Miss Bavelier said.

The researchers anticipate that video games might be particularly useful for patients suffering from conditions such as amblyopia, or "lazy-eye" -- a situation where one eye becomes stronger and the visual-nerve system suppresses the image from the weaker eye.

While corrective lenses or surgery may be needed to deal with the underlying cause, visual exercises along with eye patching and medications are often part of follow-up therapy.

Miss Bavelier said video games might even be useful in stemming visual impairment resulting from normal aging of the brain.

Only certain games -- first-person action games that require, say, spotting a target and shooting at it -- have the desired effect. Slower, puzzle-style games, like "Tetris," showed no effect on test scores for a group of Rochester students who played the game daily for a month.

"When people play action games, they're changing the brain's pathway responsible for visual processing," Miss Bavelier said. "These games push the human visual system to the limits and the brain adapts to it. That learning carries over into other activities and possibly everyday life."

Previous studies have shown that some video games also can improve hand-eye coordination, and some professionals like surgeons and pilots use them to keep sharp.

On the downside, research suggests that too much time on a bright screen can cause eyestrain and may disrupt the body's biological clock, particularly if played just before bedtime, and that some games may be psychologically damaging.