optical illusion relex by amazing madtionshion

Within visual perception an optical illusion also called a visual illusion[2] is an illusion caused by the visual system and characterized by a visual percept that arguably appears to differ from reality Illusions come in a wide variety their categorization is difficult because the underlying cause is often not clear[3] but a classification[1][4] proposed by Richard Gregory is useful as an orientation According to that there are three main classes physical physiological and cognitive illusions and in each class there are four kinds: Ambiguities distortions paradoxes and fictions [4] A classical example for a physical distortion would be the apparent bending of a stick half immerged in water an example for a physiological paradox is the motion aftereffect (where despite movement position remains unchanged) [4] An example for a physiological fiction is an afterimage[4] Three typical cognitive distortions are the Ponzo, Poggendorff, and Müller-Lyer illusion[4] Physical illusions are caused by the physical environment e g by the optical properties of water [4] Physiological illusions arise in the eye or the visual pathway eg from the effects of excessive stimulation of a specific receptor Cognitive visual illusions are the result of unconscious inferences and are perhaps those most widely known [4] by