My vision is actually pretty good. I needed glasses when I was about 20 then around 25 or so I didn’t need them anymore. On average I spend about 6 to 10hr a day on my system for work and fun. I’ve been a hardcore PC FPS gamer for about the last 17 years starting with Wolfenstein 3d. There’s an interesting stud I was reading about action games improving eye sight, take a look.

http://news.bbc.co.uk/2/hi/health/7967381.stm