Judged: two independent readers; copy check clear.
contrast illusion
contrast illusion A contrast illusion is a perceptual effect in which nearby parts of a stimulus change how one part is seen, so that features such as brightness, color, or size appear different because of their context.
A contrast illusion is a perceptual effect in which nearby parts of a stimulus change how one part is seen, so that features such as brightness, color, or size appear different because of their context. In size-contrast forms such as the Ebbinghaus–Titchener illusion, surrounding elements can make a central object look larger or smaller than it would appear on its own.