or Optical art
Branch of mid-20th-century geometric abstract art that deals with optical illusion.
Op art painters devised complex optical spaces by manipulating repetitive forms such as parallel lines, checkerboard patterns, and concentric circles or by creating chromatic tension from the juxtaposition of complementary colours, thereby creating the illusion of movement. Principal artists of the Op movement in the late 1950s and the '60s include Victor Vasarely , Bridget Riley (b. 1931), and Larry Poons (b. 1937).