(movement, mid 1960's)
Movement that developed in the United States and Europe in the mid-1960s. Deriving from the abstract expressionist movement, op art includes paintings concerned with surface kinetics. Colors were used in creating visual effects, such as afterimages and trompe-loeil. Vibrating colors, concentric circles, and pulsating moire patterns were characteristic of works by Victor Vasarely, Richard Anusziewicz, Bridget Riley, Ad Reinhardt, Kenneth Noland, and Larry Poons.