Op Art emerged between 1964-1969 and exploited optical illusions and effects of perception through geometric forms and patterns. The artists manipulated elements like light, color, and repeating lines to produce visual illusions that sometimes gave the illusion of movement, vibration, or warping in the viewer's mind. Key Op Art artists included Carlos Cruz-Diez, Bridget Riley, and Victor Vasarely, who were known for works exploiting optical effects through geometric patterns, color fields, and repeating lines.