20 Amazing Optical Illusions - The List Universe

20 Amazing Optical Illusions - The List Universe: "An optical illusion is always characterized by visually perceived images that, at least in common sense terms, are deceptive or misleading. Therefore, the information gathered by the eye is processed by the brain to give, on the face of it, a percept that does not tally with a physical measurement of the stimulus source. This is a list of twenty amazing illusions."