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Optical Illusions

  1. Anya Hurlbert

Published Online: 15 JUL 2004

DOI: 10.1002/3527600434.eap637

Encyclopedia of Applied Physics

Encyclopedia of Applied Physics

How to Cite

Hurlbert, A. 2004. Optical Illusions. Encyclopedia of Applied Physics. .

Author Information

  1. School of Biology and Institute of Neuroscience, University of Newcastle upon Tyne, England

Publication History

  1. Published Online: 15 JUL 2004


Visual illusions are tools with which vision scientists probe the visual system. Illusions are misperceptions of reality; some arise from limitations of the eye in image formation, and are rightly called optical illusions; some from neural adaptation, others from fundamental mechanisms of image reconstruction and interpretation that must operate even in the presence of inadequate, misleading, conflicting, or no sensory information. This chapter samples illusions of these different types in the perception of different visual attributes: lightness, color, size, shape, motion, and depth.


  • visual perception;
  • color;
  • motion;
  • depth;
  • lightness;
  • brightness;
  • simultaneous contrast;
  • perceptual constancy;
  • adaptation;
  • aftereffects;
  • image ambiguity;
  • perceptual reversals;
  • the Gelb effect;
  • White's illusion;
  • Mach card; Müller–Lyer illusion;
  • Necker cube;
  • watercolor effect;
  • Ames room;
  • moon illusion;
  • apparent motion;
  • chromostereopsis;
  • Johansson figures