Bridget Riley had her breakout in the early 60s painting black and white Op Art, what we'd think of now as optical illusions. These tend to induce odd sensations akin to vertigo when viewed. Here we'll do a take on op-art waves -- Precise alternating stripes that warp into rhythms across the panel. The image vibrates because the frequencies are tuned to flicker against the eye, not to depict anything.