Chubb Illusion

The Chubb effect, or Chubb illusion, is a phenomenon demostrating the effects of proximity of textures with different contrasts.

In the classic experiment, if a circle with a texture is surrounded by a solid color, it appears to be of higher contrast than the same circle surrounded by a high-contrast texture.

This illusion owes its name to Mr. Chubb and its colleagues, who discovered the phenomenon in 1989.

Chubb illusion: the central circle appears to have different contrast in the two pictures, but the two circles are exactly the same

The effect can be revealed by separating the circles from their surroundings: it is now evident the circles are the same