Introduction

This web site illustrates a new theory of visual illusions, which I developed. The theory is of a computational nature. It predicts many of the well known geometric optical illusions, illusions of movement in line drawings, as well as illusions of three-dimensional shape.

If you search the net you will find many sites on optical illusions. And if you search for explanations, you will probably form the opinion that nearly every illusion has a different cause. This is also the dominant view nowadays in the scientific community. Most involved in the study of perception would agree with Robinson who writes in his introduction to geometrical optical illusions: "There is no better indicator of the forlornness of this hope [the hope of some to find a general theory] than a thorough review of the illusions themselves ".

Illusions are fascinating to most people. Some of the illusions have been known since antiquity. The scientific study of illusions dates back to the beginning of the nineteenth century when scientists got interested in perception. Since then there has been enduring interest, and illusions have been used as tools in the study of perception. An important strategy in finding out how perception operates is to observe situations in which misperceptions occur. By carefully altering the stimuli and testing the changes in visual perception psychologists tried to gain insight into the principles of perception.

Theories about illusions have been formulated ever since their discovery. Some of the more famous theories on geometric optical illusions which can account for a number of illusions are listed here. Other theories and studies which are somewhat related to the this theory are listed here. The new theory is described in the following papers.