Computer and video games that involve guns and shooting may not do much for a child's education but they can improve eyesight, according to a study showing that a person's night-time vision gets better after playing electronic action games.
Scientists found that games involving aiming and shooting at virtual objects on a computer screen can significantly increase people's ability to see objects in twilight conditions, when colours fade into different shades of grey.
Until now the only recognised way of improving a person's ability to detect small changes in shades of grey – visual "contrast" – was to improve the optics of the eye with contact lenses, spectacles or surgery.
But researchers have found that training on a video game can be just as effective, if not more so.
"Unfortunately, contrast sensitivity is one of the aspects of vision that is most easily compromised," said Daphne Bavelier, professor of brain and cognitive sciences at the University of Rochester in New York, who led the study published in the journal Nature Neuroscience.
"This problem affects thousands of people worldwide, including those with professional activities requiring excellent eyesight, and ageing populations, along with individuals who are clinically evaluated for vision problems such as amblyopia," Professor Bavelier said. "Normally, improving contrast sensitivity means getting glasses or eye surgery, somehow changing the optics of the eye. But we have found that action video games train the brain to process the existing visual information much more efficiently. The improvements last for months after game play has stopped."
The scientists tested the contrast sensitivity of a group of people who regularly played action video games, such as Unreal Tournament and Call of Duty, where the player has to shoot at virtual targets. They found the group's ability to detect different shades of grey was 58 per cent better on average than people who had not played the games.
Those who were not regular game players were then put through a training regime involving hours of console gaming. When they had completed the course, their contrast sensitivity had improved by 43 per cent on average.
"People who played action video games have better vision in the sort of conditions where there is not much contrast," said Professor Bavelier.
"It can make all the difference when driving at dusk, or in fog, in being able, for instance, to see a dog crossing the road in twilight.
"There are practical benefits for people who rely on their eyesight for their work, such as the military or commercial airline pilots.
"It shows that if you need to improve your vision, you can train your brain to get better at using the visual information you get," she said.