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. A conventional assumption is that there are physiological illusions that occur naturally and cognitive illusions that can be demonstrated by specific visual tricks that say something more basic about how human perceptual systems work. | 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. A conventional assumption is that there are physiological illusions that occur naturally and cognitive illusions that can be demonstrated by specific visual tricks that say something more basic about how human perceptual systems work. |