Optical illusion art, also known as op art, is a mathematically-based genre that produces optical illusions. It uses the repetition of form and color to create moiré patterns that give rise to illusions. It also distorts our sense of depth, causing foreground-background confusion, as well as other perplexing effects.
Optical illusion art requires math ingenuity, technical skills and meticulous planning. Because it manipulates the rules of perception, a viewer trying to decipher such a painting may observe movement, hidden images, three-dimensional forms, and other simulation.