Hilary_Truong

Perceptual constancies are sources of illusions. Color constancy and brightness constancy are responsible for the fact that a familiar object will appear the same color regardless of the amount of light or color of light reflecting from it. An illusion of color or contrast difference can be created when the luminosity or color of the area surrounding an unfamiliar object is changed. The contrast of the object will appear darker against a black field that reflects less light compared to a white field even though the object itself did not change in color. Similarly, the eye will compensate for color contrast depending on the color cast of the surrounding area.