Take the Test Here
There are lots of these types of vision tests out there, and most are facebookily irritating, but this one from Finland is pretty awesome. With increased difficulty, you have to select the square that doesn’t match the rest. Piece of cake with the one on the left, but then you’re under time pressure with smaller squares like the one on the right. I’m not sure if it’s more vision test or more game, but I like it cuz I’m good it. (Note: play on mobile device and turn up brightness — I think it’s better that way.)