In a study published by Nature Neuroscience, it was revealed that playing video games can improve a person's sensitivity to visual contrasts. The authors of the study write, "The contrast sensitivity function (CSF) is routinely assessed in clinical evaluation of vision and is the primary limiting factor in how well one sees. CSF improvements are typically brought about by correction of the optics of the eye with eyeglasses, contact lenses or surgery. We found that the very act of action video game playing also enhanced contrast sensitivity, providing a complementary route to eyesight improvement."
According to the LA Times, "Contrast sensitivity function refers to the ability to detect small differences in shades of gray, and it is one of the most vulnerable elements of vision. Scientists believe it is affected by deterioration of the eye itself."
The subjects of the study were people in their 20s who were new to playing video games. The games used in the study were Unreal Tournament 2004, Call of Duty 2, and The Sims 2. Participants were encouraged to play their assigned games for a total of fifty hours over a nine-week period.
Although all participants saw benefits, the improvements in participants' CSF were particularly noteworthy for those who played the action games--averaging about 58%. The effects were shown to last for months and, in some cases, for years.