false eye

A false eye is a marking on an animal that resembles an eye, typically found on butterfly wings, moth wings, or fish bodies.

These eyespots serve as defense mechanisms—startling predators or directing attacks away from vital areas: The butterfly's false eyes made it look like a much larger creature.

False eye also refers to a prosthetic eye worn by someone who has lost an eye, though "glass eye" or "prosthetic eye" are more common terms for this meaning.