Well, if you happen to have an eye disorder. Daphne Mauer, a psychologist at McMaster University in Ottawa, Canada, gave people first-person shooter games to play for 40 hours a week. Why first-person shooter? Because, as the Guardian points out, they “require players to respond to action directly ahead of them and in the periphery of their vision, and to track objects that are sometimes faint and moving in different directions, strengthened the visual system in adults whose eyesight had been severely impaired from birth.”
Mauer worked with patients (19-31 years old) who were born with dense cataracts, which “block out almost all detail of the visual world, except distinct changes in light or dark.” Cataracts like these, as well as amblyopia (lazy eye), were previously thought to be unable to be repaired or improved. After going through the study, patients were able to read around two lines lower on an eye chart than previously.