Illusion

An illusion is a perception which does not correspond to reality. Each of the human senses can be deceived by illusions, but visual illusions are the most well known. Illusions are subjective; different people may experience an illusion differently, or not at all.

• Optical illusions, such as mirages, exploit assumptions made by the human visual system.
• Auditory illusions, such as the Shepard Tone, exploit our hearing.
• Touch illusions exploit our sense of touch.
• Stage magic is a popular form of entertainment based on illusion. Magicians use tricks to give their audiences the impression that seemingly impossible events have occurred. See magic (illusion).
• Mohammed Saeed al-Sahaf often claimed US war successes to be an illusion.

See also:

• delusion
• simulated reality for a more radical approach to the possibility of illusion