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
Fraser spiral illusion Fraser spiral illusion The Fraser spiral illusion is an optical illusion that was first described by the British psychologist Sir James Fraser (1863 – 1936) in 1908. The illusion is also known as the false spiral, or by its original name, the twisted cord illusion. The overlapping black arc segments appear to form a spiral; however, the arcs are a series of concentric circles. The visual distortion is produced by combining a regular line pattern (the circles) with misaligned parts (the differently colored strands). Zöllner's illusion and the café wall illusion are based on a similar principle, like many other