Aside from magic tricks, the most spectacular visual illusions are those created in the brain itself. The most famous illusions in psychology are the Mueller-Lyer illusion (two lines with opposing arrowheads), the impossible triangle, and the Necker cube. Optical illusions were exploited in optical art, and by artists such as Escher and Dali. The variation in the apparent size of the Moon (larger when near the horizon) is an example of a natural illusion that is an optical phenomenon.

Free Screensaver for Windows

Contains the best optical illusions, illustrating a wide range of visual anomalies and surprising optical effects. They fool your mind into seeing a false reality. Identical lines will appear to be different lengths, ghostly dark blobs appear where the screen is white, black and white patterns appear to move when they can't, etc. They can be so convincing that you may have to check for yourself that there's no trickery involved!

Click download, and then select 'Open' to install automatically. Approximately 700 Kb. Last update 22nd April 2003.