Playing high-action video games for a few hours each day can improve your vision, according to researchers in the US. But an eye expert in the UK called their findings into question.
The researchers from the University of Rochester in New York found that people who play video games for a few hours a day over the course of a month can improve certain aspects of their vision by about 20 percent.
Playing the games changes the pathways in the brain responsible for visual processing, as the brain adapts to the additional pressure that playing such games puts on the visual system, they said.
The researchers found a group of students who played little or no video games -- which was a challenge in itself -- and gave them a test that measured how well they could discern the orientation of a letter "T" within a crowd of other, distracting symbols.
They then divided the students into two groups. One group was told to play the shoot-em-up game "Unreal Tournament" for an hour each day for a month, while a control group played "Tetris," a less visually complex game.
After about a month, the students playing the action game could determine the orientation of the "T" much more easily than before, while the Tetris players showed no improvement, the researchers said.
The T test measures visual acuity, or the clarity of a person's vision, according to the researchers, who are Daphne Bavelier, a professor of brain and cognitive sciences, and graduate student Shawn Green.
That means playing video games should improve your ability to identify letters on a standard eye-test, they claim.
An optometry expert in the UK disagreed, however. The American researchers are confusing visual acuity with visual search, which is what the T test really measures, according to Maggie Woodhouse, a senior lecturer in the School of Optometry and Vision Sciences at Cardiff University.
"The test they're using is not for visual acuity," she said after being told of the research. "They've trained their students to make rapid eye movements and to scan large areas to find objects of interest. ... That is visual search."
There may indeed be a benefit from playing high-action video games, she said, but it will be in the ability to locate objects in a large or crowded area. That means it could help you pick out a friend's face at a football game, or play a fast-moving sport like ice hockey.
The improvement may not last for very long, however, and Woodhouse seemed to consider the overall impact of video games a negative one. Playing for too long can cause eye strain, she said.
The researchers at Rochester University could not immediately be reached for comment. They said the results of their test suggest that people with visual defects could improve their visual acuity with special software that mimics the need to identify objects quickly in an action game.
The research is due to appear in next week's Psychological Science journal.