Focus is a Flash animation made by Wally Bartus on Albino Blacksheep.
This Flash animation makes you focus on a black and white picture, making you believe your vision will be distorted. However, after about 10 seconds, a picture of an overweight woman showing her rear end appears along with a fart sound. Then, some text appears saying "Gotcha, didn't I? Hahaha!"
NOTE: The following animation contains a screamer!