Practiced from South America to Europe, Op Art (or Optical Art) was an international art movement during the 1960s, which presented a new form of abstraction that played with the viewer’s visual perception. Often considered the “grandfather” of Op Art, French-Hungarian artist Victor Vasarely began creating mind-bending paintings as early as the 1930s, leveraging his studies of science, color, and optics to produce images that seemed to move, swell, or change forms. In 1965, The Museum of Modern Art presented a survey of Vasarely’s followers in a seminal exhibition titled “The Responsive Eye,” showcasing works by Richard Anuszkiewic, Bridget Riley, Carlos Cruz-Diez, Jesús Rafael Soto, and Josef Albers, among others. Fashion brands soon popularized the bold patterns of Op Art through their “Mod” designs, while art critics like Clement Greenberg critiqued the movement for its gimmicks and commercial appeal. Op Art continues to be influential today, inspiring both artists and neuroscientists to take a closer look at how the eye processes lines, forms, and colors.