Optical Illusion

An optical illusion, also termed as visual illusion, is an image that can deceive or trick our perception.

According to Richard Gregory, the three classifications of optical illusion are physical, physiological, and cognitive.

* Physical illusion is caused by the physical environment such as when mountains appear to be nearer when there is low humidity during clear weather. * Physiological illusions involve the visual mechanism and how the optical information is processed in the brain. For instance, you may see certain after images after looking at a very bright light. * Cognitive illusions involve unconscious factors and previous experiences. For instance, in the famous rabbit-duck illusion (hyperlink), you may first see the duck if you are often exposed to such animals and vice versa. Moreover, it may be more difficult for some individuals to immediately perceive the rabbit if they could not readily organize the incoming visual sensation into more meaningful personal information.