Op art is art which uses color and abstract patterns to create an illusion of pulsing movement. The name was coined in 1964 by Time magazine, a takeoff on the term "pop art," which had been coined a few years earlier, in combination with the word "optical." It was perhaps more of a fad than a major movement, and was very popular in the sixties when op art seemed to evoke visual sensations similar to those induced by psychedelic drugs.
The visual effects induced by op art may be partly due to a moire effect occurring between the geometrical pattern and its afterimage, shifting as a result of eye movement.
Important artists in the style included Bridget Riley and Victor Vasarely.