Optical illusions

Here is an awesome optical illusion, that involves watching a rotating spiral then looking at ones hand (via Hotlinks, flash).
This led me to Michael Bach's site which has tons of motion-related illusions, including my grandpa's "Enigma".
Akiyoshi Kitaoka authored other very effective motion-related illusions (via Boing Boing).

Here's another one, related to the language centers and the visions centers interfering: read out the color of the words.
Fabrice also seems to be an amateur of these and links to a couple.

Argh. Some of these illusions just don't work very well for me. I don't know why.

Here's another cool optical illusions link for ya!

http://www.coolopticalillusions.com

optical illusions