Optical Illusions

Optical Magic Optical Illusions - A selection of common images.
http://www.goodtricks.net/optical-illusions-optical-magic.html

Subliminal Messages - Impossible figures, optical illusions, multimedia and 3D puzzles.
http://www.subliminalmessages.com/

IllusionWorks - A multimedia museum of optical and sensory illusions, with online demonstrations and explanations.
http://psylux.psych.tu-dresden.de/i1/kaw/diverses%20Material/www.illusionworks.com/

Eyetricks.com - Optical illusions, 3D stereograms and anaglyphs, fractals and brain teasers
http://www.eyetricks.com/

Mindfake.com - A collection of optical illusions, online games, and other fun things.
http://www.mindfake.com

Optical illusion - A large collection of optical illusions.
http://www.optical-illusion.org/

NBCreations illusions - Illusions by Brincat Norbert for viewing and downloading.
http://nbcillusions.100freemb.com

Optical Illusions - Amazing Pictures and Effects
http://www.panoptikum.net/optischetaeuschungen/opticalillusions.htm

All In Fun Magic - Over 50 optical illusions and ambiguous drawings.
http://www.allinfunmagic.com

Planet Perplex - Selection of optical illusions, hidden images, impossible objects and upside down images.
http://www.planetperplex.com

Cool Optical Illusions - A growing collection of optical illusions and eye tricks, including original illusion pictures and a collection of optical illusion desktop wallpaper.
http://www.coolopticalillusions.com

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.
http://eluzions.com/Illusions/

The McCulloch Effect - An On-line Science Exhibit - The stress here is on relative novelty and interactivity, in combination with a scientific background. Regularly updated.
http://research.lumeta.com/ches/me/

Braingle's Optical Illusions - Dozens of optical illusions to tease your brain.
http://www.braingle.com/brainteasers/optical-illusions.php

Amazing Eyetricks - Gallery of pictures that will trick your eyes.
http://www.fun4all.dk/eyetricks/

Amos Storkey - Visual Illusion of the Month - Collection of illusions and images chosen for novelty and distinction from the usual set found in most collections.
http://www.anc.ed.ac.uk/~amos/visualillusion.html

Skytopia - Dynamic Optical Illusions - A selection of old, new and original optical illusions. Many pictures are enhanced via the use of 3D and animation.
http://www.skytopia.com/project/illusion/illusion.html

Eye Magic: Optical Illusions - Offers a number of optical illusions for viewing, as well as explanations on how they work.
http://www.harmsy.freeuk.com/eyemagic.html

Optical Illusions Etc - A collection of various forms of optical illusions with explanations, including illusions conveyed through fractals, architecture, art, advertising and real life encounters.
http://illusionsetc.blogspot.com

Akiyoshi's illusion pages - Many works of Akiyoshi Kitaoka. Designs around standard illusions crafted to maximise the illusory effect.
http://www.ritsumei.ac.jp/~akitaoka/index-e.html

Cut the knot: Visual Illusions - A collection of about 20 illusions - all accompanied by Java applets. Interactively changeable attributes help investigate which ones are in fact responsible for tricking the brain.
http://www.cut-the-knot.org/Curriculum/index.shtml#illusions

Just Optical Illusions - Focus on geometric optical illusions by Gianni A. Sarcone and Marie J. Waeber
http://www.geocities.com/just_optical_illusions/

Optillusions - A collection of riddles and optical illusions of many different forms with thumbnail browsing.
http://www.optillusions.com

Optical Illusions? - Comments on the terms 'Optical Illusion' and 'Visual Illusion'.
http://www.anc.ed.ac.uk/~amos/opticalillusion.html

Optical Illusionist - Optical illusions, eye tricks, mind teasers and other puzzles.
http://www.optical-illusionist.com

Optical Illusion Archive - A collection of optical illusion images, 3D street art, and flash demonstrations.
http://www.unoriginal.co.uk/optical1.html