The improvement was remarkable: among a study group of non-gamers that were told to play action video games for a few hours a day, they improved their eyesight by 20 percent within one month.
The important factor was the type of gaming you do: Pac Man, Zelda and Mario aren't going to improve your eyesight; searching for fast-moving targets onscreen in a gaming environment with dark and light areas, like in Halo, will.
This is because action gaming has a different effect on our brains, Daphne Bavelier, professor of brain and cognitive sciences, said in the study.
"Action video game play changes the way our brains process visual information," she said. "After just 30 hours, players showed a substantial increase in the spatial resolution of their vision, meaning they could see figures like those on an eye chart more clearly, even when other symbols crowded in."
To see if there was any improvement, the researchers used test subjects who rarely play video games. The study had one set of players play Tetris and the other set play Unreal Tournament, a shooting game.
In comparative eye chart tests, only the players who played Unreal showed visual improvement. The shoot-'em-up players also could correctly identify objects faster than the Tetris players.
"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," Bavelier said in a press release.
The research suggests that action gaming can help improve the eyesight of people with visual defects.
The team is now going to research further into how the brain responds to other visual stimuli. They will be using a massive 360-degree enclosed gaming environment for their next study.
The Unreal/Tetris study will appear in next week in the journal Psychological Science.