Optical illusion There are a variety of different types of optical illusions. Many are included in the following list. Artists who have worked with optical illusions include M. C. Escher, Bridget Riley, Salvador Dalí, Giuseppe Arcimboldo, Patrick Bokanowski, Marcel Duchamp, Jasper Johns, Oscar Reutersvärd, Victor Vasarely and Charles Allan Gilbert. Contemporary artists who have experimented with illusions include Jonty Hurwitz, Sandro del Prete, Octavio Ocampo, Dick Termes, Shigeo Fukuda, Patrick Hughes, István Orosz, Rob Gonsalves, Gianni A. Sarcone, Ben Heine and Akiyoshi Kitaoka. Optical illusion is also used in film by the technique of forced perspective. Op art is a style of
Ebbinghaus illusion of smaller. Sarcone's Cross illusion consists of a cross (the test shape) surrounded by sets of squares of distinct size (the inducing shapes). As shown in the diagram opposite, the three blue crosses are exactly the same size; however, the one on the left (fig. 1) tends to appear larger. The illusion works even when the small squares completely occlude the blue cross (see fig. 3). In conclusion, there isn’t always correlation between the size of the surrounding shapes and the relative size perception of the test shape. Ebbinghaus illusion The Ebbinghaus illusion or Titchener circles is an optical illusion