http://norman.walsh.name/2003/09/09/badeyes 6 82 2003-09-09 $Date: 2005-09-11 10:27:02 -0400 (Sun, 11 Sep 2005) $ Norman Walsh 2003 Norman Walsh Absolutely stunning optical illusions. [Updated: 16 Sep 2003 with another.] Swift Vision is the art of seeing things invisible. I think optical illusions are pretty neat. I had a few books of them when I was a kid and I enjoyed the random dot stereogram craze a few years back. It never occurred to me to go looking for optical illusions on the web, there are probably zillions of examples, but I stumbled across a link to Akiyoshi's illusion npages earlier today. I'm just amazed. They are stunningly good. Worth a peek. [Updated 15 Sep 2003] And here's another that drifted across my desk: checker-shadow illusion. I'll save you the trouble of firing up Gimp to prove it isn't true: it is. Both squares are #6B6B6B.