See For Yourself - Purves Lab's optical illusions web page with empirical explanations of familiar and unfamiliar illusions.
posted by nthdegx on Nov 16, 2007 - 6 comments

Is the dancer spinning clockwise or counterclockwise? An optical illusion. [more inside]
posted by painquale on Oct 8, 2007 - 133 comments

Your daily dose of perception-bending. Stare at the center of this video (wmv or flash) for a minute or two then look away from the screen at your surroundings. You'll experience an interesting and somewhat disconcerting effect. Not appropriate for anyone prone to headaches or seizures.
posted by brain_drain on Aug 28, 2006 - 51 comments

Rapid Afterimage Optical Illusion
posted by srboisvert on Jun 6, 2005 - 38 comments

Interesting Optical Illusion - and explanation. {It's just a single page with an image. Go on, click it!}
posted by dobbs on Nov 13, 2004 - 24 comments

Utterly terrifying! [Windows Media, from Grand Illusions]
posted by Pretty_Generic on Nov 13, 2004 - 15 comments

This is the coolest optical illusion you'll ever see. Happy Friday. (Warming: .exe format, about 250k)
posted by skechada on Jan 10, 2002 - 17 comments