Perceptual illusion in which an artificial blind spot is filled in by a twinkling background.
Brocken spectre
Optical illusion in which the apparently greatly magnified shadow of an observer, when projected onto a surrounding mist, interferes with the observer's depth perception.
Checker shadow illusion
Perceptual illusion demonstrating that the visual system uses context as well as physical luminance to determine the lightness or darkness of an object.
Fantascope
Redirected to phenakistoscope.
Grey Man
Redirected to Brocken spectre.
Orgone
Widely discredited theory of universal life energy developed by the Austrian psychiatrist Wilhelm Reich (1897–1957).
Orgonomy
Redirected to orgone.
Phantasmascope
Redirected to phenakistoscope.
Phenakistoscope
Optical toy producing the illusion of moving images, popular during the Victorian era.
Troxler Effect
Perceptual illusion in which an image in peripheral vision disappears.