Sometimes out of boredom, I can look at a wall, with very little light in a room and if I stare at it long enough black spots will appear and eventually merge together making me completely blind, with my eyes wide open. I can usually hold it for awhile too, that is, until I move my eyes. What is that? Anyone ever do this before? Is it like my brain taking a pattern I’m focusing on and duplicating it? Weird.
It’s your brain’s screensaver 
Duplicate of Staring into nothingness and going temporarily blind.
I’ll close this one.
DrMatrix - GQ Moderator