If you are having difficult in driving at night, or having a hard time to Photoshop designing, look no further than picking up a first person shooting (FPS) game from Best-Buy and starting playing it.
Study conducted by researchers at University of Rochester demonstrated playing video games, such as Unreal Tournament or Call of Duty 2, could significantly improve one's vision, especially in the contrast sensitivity. The lead research, Mr. Li Renjie is a PhD candidate who identifying himself of a broad range of interests including 'playing video games'. Go figure. Li graduated from USTC of China in 2004.
The full text brief communication which is titled "Enhancing the Contrast Sensitivity Function Through Action Video Game Training" is published online by Nature Neuroscience on March 29, 2009. The group also have a range of publications on impact of playing video games on human vision, by and large positive.