This has happened to me a few times as well - usually when I stare into the computer screen for too long (you don't want to know how many hours in a row, trust me), I get headache and my vision goes all weird. Usually helps when I take a break, bath, shower, whatever.
abbot common stop bad for you if u watch anime all day nigga u fuckn weaboo
You shouldn't sit there staring at the TV/COMPUTER all day. It's really bad for you.