Optical Illusions are visually perceived images that are misleading to the human mind. The information gathered by the visual cortex gives the brain a perceived image that is not identical to the source of the stimulus. This causes the individual to perceive something different than reality. There are two main types of optical illusions, physiological illusions and cognitive illusions.

Physiological illusions are created when the eyes are exposed to excessive amounts of a specific stimulation such as brightness, tilt, color or movement. An example would be the afterimages caused by quickly alternating patterns and bright lights such as the sensation experienced after looking at the sun for a prolonged period of time.

Instead of being created by stimulation, Cognitive illusions base themselves on the individual’s understanding of the world and assumptions. Cognitive illusions are divided into three subunits. These are ambiguous illusions, distorting illusions, and paradox illusions.

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