Optical Art, or Op Art, developed as a segment of geometric abstraction in the mid-20th century. Concerned with perception and visual phenomena, images were intended to surprise the viewer and provoke visual confusion. Paintings generally employ hard-edge line, chromatic relationships, tonal contrast, and figure/ground ambiguity to create optical illusions of movement and shifting special depth. Patterns, shapes, and forms appear simultaneously to come forward or recede, and are not easily reconciled. The viewer becomes an interactive participant and is acutely aware of the act of seeing through noticeable visual sensations such as pulsating, vibrating, or difficulty focusing. Op Art compositions became popular with graphic and fashion designers in the 1960s and 1970s, and led to further experimentation with optical illusions in media such as television and video. Selected works from the museum collection include paintings by Richard Anuszkiewicz, Karl Benjamin, Samia Halaby, Howard Mehring, Peter Sedgley, and Victor Vasarely.