More specifically it trains what eye doctors call "contrast sensitivity", - the ability to notice tiny shades of grey against a uniform background - which often degrades with age but is critical to everyday activities such as reading and driving at night.

Contrast sensitivity is normally corrected by getting glasses or having laser surgery but it has been discovered that shooters can allow the skill to be trained which was a surprise.

"This is not a skill that people were supposed to get better at by training," said Daphne Bavelier, a professor at the University of Rochester in New York state and the study's lead researcher. "What we found is that even without this correction you can help your brain make better use of whatever information is received from your retina," she said.

In the study the researchers compared to the contrast sensitivity levels of hard-core action game players with casual gamers of the same age group. The researchers found that the hardcore gamers were 50% more efficient at detecting the contrast compared to the casual gamers.

In order to determine whether their vision had improved through playing or did they play shooter games because they had a strong contrast sensitivity to begin with, a further experiment was conducted.

Two groups of casual gamers were asked to undergo 50 hours of training, one played Call of Duty while the other played "a game that offered a rich visual experience, but one bereft of action." The results supported the initial theory that shooter games improve vision. "We found that the people in the first group improved by 43 percent, and the other group not at all," said Bavelier.

Furthermore the effects are not temporary. "The positive effect remained months, even years after training, indicating long-lasting gains." When asked if there is a limit to the positive effect the games could have on a players vision Bavelier replied "for your visual system, probably not. For your social life, perhaps."

News.com / via Kotaku