Vision & Illusions

Learn about visual perception – what we "see" is sometimes an optical illusion.

Our brain, eyes, and nerves can fool us. This is the basis for many interesting optical illusions. It is also the basis for a field of research, a subdivision of psychology, known as Gestalt Theory. This app, designed to be both informative and interesting, introduces principles of Gestalt perception, as well as other surprising visual effects that you have to see to believe. Animation has been used extensively to illustrate the nature of our perceptual patterns. So, whether you're preparing for an exam in Psychology 101, or simply interested in optical illusions, you will find dozens of intriguing examples of how our mind and eyes are both involved in seeing things.

Gestalt means "unified whole." The Gestalt effect refers to the capability of our senses to generate unified impressions that ignore details. Visual Gestalt principles of grouping were introduced in the 1920s by Max Wertheimer. The Gestalt principles that he and his contemporaries introduced are presented here so that you can develop fuller understanding of how vision, visual illusions, and perceptual biases operate. Through the use of examples we can see how this capacity causes us, in some cases, to form inaccurate impressions.

Included in this free app are demonstrations of numerous visual illusions and optical effects, including the Troxler Effect, Ebbinghaus Illusion, Poggendorf Illusion, Müller-Lyer Effect, dynamic multistability, static multistability, the Ames Window, and more. A separate section introduces seven basic principles of Gestalt. All of these effects and illusions are accompanied by explanatory info.

Unlike many existing apps and websites, the examples here are dynamic, using animation and interactivity to enhance the experience. It even uses some audio. You may be surprised by the strange and unexpected ways that your eyes and brain make assumptions about the visual world. It's fun, thought-provoking, and educational.