Rational Egoist writes: "A new study from Tel Aviv University shows that teens who played violent video games, such as UT2k4 and Call of Duty 2, enhanced their ability "to discriminate between subtle contrasts in color or shades of gray", as compared to teens playing games with lower levels of visual-motor coordination, such as The Sims. From the article: "After playing 50 hours of the assigned game over 9 weeks, the students who played the more violent action games showed a 43% improvement, on average, in their ability to discern between very close shades of gray. The players assigned to the Sims game showed no improvement." It's even being suggested as a possible alternative to eye surgery. The full article is available online from Nature Neuroscience."