Optical Illusions

Product Information

Troxler's fading: When one fixates on a particular point for even a short period of time, an unchanging stimulus away from the fixation point will fade away and disappear. He taught science and creative writing in elementary and secondary schools and was chair of the science department at a junior high school in the New York City public school system before leaving to become a full-time writer. "I haven't really given up teaching," he says, "and I suppose I never will, not as long as I keep writing and talking to kids around the country and the world."

Bertamini M. Ponzo illusion. In: Programming Visual Illusions for Everyone. Vision, Illusion and Perception, vol 2. Springer, Cham; 2018. doi:10.1007/978-3-319-64066-2_5 The Poggendorff illusion (1860) involves the misperception of the position of one segment of a transverse line that has been interrupted by the contour of an intervening structure (here a rectangle).Lucafò C, Marzoli D, Prete G, Tommasi L. Laterality effects in the spinning dancer illusion: The viewing-from-above bias is only part of the story. Br J Psychol. 2016;107(4):698-709. doi:10.1111/bjop.12166 Weidner R, Boers F, Mathiak K, Dammers J, Fink R. The temporal dynamics of the Müller-Lyer illusion. Cerebral Cortex. 2010;20(7):1586-1595. doi:10.1093/cercor/bhp217

An afterimage or ghost image is a visual illusion that refers to an image continuing to appear in one's vision after the exposure to the original image has ceased. An autostereogram is a single-image stereogram (SIS), designed to create the visual illusion of a three-dimensional (3D) scene from a two-dimensional image in the human brain. An ASCII stereogram is an image that is formed using characters on a keyboard. Magic Eye is an autostereogram book series. The Moon illusion is an optical illusion in which the Moon appears larger near the horizon than it does while higher up in the sky. Powell G, Bompas A, Sumner P. Making the incredible credible: afterimages are modulated by contextual edges more than real stimuli. J Vis. 2012;12(10). doi:10.1167/12.10.17 The Kanizsa triangle is an optical illusion first described by the Italian psychologist Gaetano Kanizsa in 1955. It is a triangle formed of illusory contours.

Candle

A type of multistable illusion where an image of a concave object, rotated so that the light source is below, may sometimes appear convex, and vice versa. This phenomenon is due to the fact that light sources tend to shine from above the subject.