Kinetic art expressions based on optical and luminous phenomenon as well as painting illusionism. The expression "kinetic art" in this modern form first appeared at the Museum für Gestaltung of Zürich in 1960, and found its major developments in the 1960s. In most European countries, it generally included the form of optical art that mainly makes use of optical illusions, such as op art, represented by Bridget Riley, as well as art based on movement represented by Yacov Agam, Carlos Cruz-Diez, Jesús Rafael Soto, Gregorio Vardanega, or Nicolas Schöffer. From 1961 to 1968, GRAV ("Groupe de Recherche d’Art Visuel") founded by François
Jastrow illusion the small radius. The short side makes the long side appear longer, and the long side makes the short side appear even shorter. The Jastrow illusion has been compared with other optical illusions, such as the Fat Face illusion, the Leaning Tower illusion and the Ponzo illusion. Masaki Tomonaga, a researcher at Kyoto University, compared the Jastrow Illusion with the so-called Fat Face Illusion. He conducted experiments with people and chimpanzees to compare this illusion with the classical Jastrow Illusion. Animals are known to observe many of the same optical illusions as humans do, but this was the first study