Akiyoshi's Illusion Pages: Includes anomalous motion illusions.
Art for Kids - The Boggler: A collection of interactive optical illusions. Also includes links to sections featuring famous artists, interactive drawing and puzzles.
Brain Teasers - Scary Optical Illusions: Includes ambiguity pictures, scary equivocal illusions, and moving objects illusions.
Colorcube: Illusions organized by category, including blind spot, blink effect, bordering, chromatic adaptation, colorblindness, and others.
Counter-Rotating Spirals Illusion: Java applet, including other illusions, such as an animated Necker cube.
Crazy Images: Interactive animations and optical illusions that respond to user's input.
Eluzions' Optical Illusions: Contains many optical illusions, illustrating a wide range of visual anomalies and surprising optical effects. A free screensaver, posters, and educational explanations are also provided.
Eye Magic: Collection of high quality optical illusions that come with clear explanations.
Eyetricks.com: Collection of illusions and other mind teasing oddities. Includes illusions that you can make.
Eyetricks.com: Optical Illusions: Collection of optical illusions, brain teasers and games.
Illusion Works: A multimedia museum of optical and sensory illusions, with on-line demonstrations and explanations.
M.C. Escher: Optical illusion art, news, history, copyright and foundation information.
Magic Eye Image of the Week: Includes a new image every week demonstrating stereograms.
Mighty Optical Illusions: Offers a database of optical illusions most of them real life ones.
NIEHS Kids Page -- Optical Illusions: Presented by the National Institute of Environmental Health Sciences. A collection of illusions.
Optical Illusions: Some classic optical illusions with explanations for how they work.
Optical Illusions: From the Department of Ophthalmology and Visual Science at the University of Illinois, a collection of illusions and after images.
Optical Illusions Etc: Contains many optical illusions in blog format.
Sandlot Science: Interactive optical illusions, games, science projects, fun puzzles, and distortions.
The Exploratorium's Online Exhibits: Seeing Exhibits: Interactive illusions from the exploratorium.
Visual Phenomena and Optical Illusions: Interactive illusions, including Benham's disk and other illusions involving motion.