The Oxford Dictionary of 20th Century Art defines Op Art as: "an exactly prescribed retinal response . . . repeated small scale patterns arranged so as to suggest underlying secondary shapes or warping or swelling surfaces."
But Op Art was much more than that. During the 1960s, a time when the hallucinogenic LSD was widely described as a "mind-expanding drug," Op Art zipped across boundaries of culture and politics to communicate the timely message that a new way of seeing had arrived.
The term Op Art was coined in 1964 by sculptor George Rickey (from "optical art," it also played on Pop Art). Influenced in part by scientific studies in visual perception, the originators of Op Art were Hungarian geometric painter Victor Vasarely, and a remarkable young British woman named Bridget Riley.