Chessboard Illusion (Checker Shadow Illusion)

The chessboard illusion or checker shadow illusion makes squares with identical brightness, which are partly shaded by a green cylinder, appear like a checkerboard with dark and light squares. This optical illusion was developed by Edward Adelson in 1995, an MIT professor. Adelson’s checker shadow illusion exhibits the human visual perception on the lightness or reflectance of surfaces. Specifically, the identical squares are perceived as having different shades due to simultaneous lightness contrast. This illusory effect points out that we may falsely interpret stimuli due to lighting conditions and previous sensory experience.