Optical Illusions

Our brain translates what the eye sees into visual information – and, occasionally, also into optical illusions. Our mind is used to making sense of all the images we perceive on the basis of its visual memory and completing them by means of stored experiences. This process of completion is what leads to optical illusions. These take the form of geometric illusions, colour illusions, contrast illusions and others besides. A number of examples can be used to illustrate the subjective suggestibility of our visual perceptive capacities.

This image consists of alternating dark and light squares. Light dots have been placed in some corners of the dark squares. This creates the impression that the lines separating the light and dark squares, which we know to be straight, are wraped.

The second and sixth bars in this figure appear to get wider towards the right-hand side of the image, while the fourth bar appears to get narrower. In fact, all the horizontal lines are completely parallel; none of them get wider or narrower.