Chop Cup. There is a fault in reality. Do not adjust your mind. [more inside]
posted by lazaruslong on Oct 4, 2009 - 44 comments

A truly amazing optical illusion -- despite what you first think, there are only three colors in that picture.
posted by Chocolate Pickle on Jun 24, 2009 - 111 comments

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

OLE Coordinate System is the software that drives Echochrome, an Interactive Optical Illusion. The playable demo lets you play in an Escherian space. [via]
posted by solipsophistocracy on Jul 18, 2007 - 15 comments

Andrew Lipson and Daniel Shiu build faithful, 3D versions of Escher prints using LEGOs: Relativity, Ascending and Descending, Waterfall, and Belvedere. (Only one of those four images required any photo manipulation to create its "Escher effect" -- can you tell which one, without scrolling down to see the descriptions on each page?) Other people's LEGO adventures: a playable harpsichord, the Golden Gate Bridge, and a portrait of Catwoman.
posted by allterrainbrain on Jul 8, 2007 - 17 comments

Ready for '90s nostalgia yet? Well, throw some flannel on your Furby and get ready for that decade's most migrane-tastic fad, the autostereogram, or Magic Eye. Of course, the Web can't leave anything alone, so you can watch a moving autostereogram, play a little wall-eyed Tetris or Pong, and create your own image to delight and annoy your friends.
posted by L. Fitzgerald Sjoberg on Jun 18, 2007 - 69 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

Cayetano Ferrer is a Chicago based artist whose work involves (among other styles) painting street signs with the images of the items immediately behind them, to give the illusion of transparency (depending on what angle you're viewing from). The latest campaign by Amnesty International seems inspired by his work.
posted by jonson on Jun 8, 2006 - 14 comments

Spanish Castle Magic. Stare at the dot in the center of the image for 30 seconds, then mouseover the picture. Don't shift your glance, because until you do the picture will appear to be in color, despite the fact that it's in black & white.
posted by jonson on Jun 7, 2006 - 67 comments

The world's first photograph was produced in France in about 1826. Joseph Nicéphore Niépce rendered a bitumen-on-pewter image of the view from his summer house in St-Loup de Varennes with an exposure time of ~8 hours. He dubbed the process, which used a camera obscura effect, heliography. Before he died in 1833 he worked for a few years with Louis Daguerre (yes, him) who incidentally invented the diorama, examples of which are among these other vintage optical toys.
posted by peacay on Jul 24, 2005 - 15 comments

Turn Your Head is an online service that echoes the famous "two faces/chalice" optical illusion, but in the real world. You provide them with shots of your profile, and they carve a wooden sculpture of the image for only $149.95. Works best for those with uniquely pronounced features, not to mention those with $149.95 to waste on useless crap.
posted by jonson on Jul 5, 2005 - 21 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

These links are probably best viewed only by the blind.
posted by crunchland on Jan 8, 2003 - 32 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