Benham Disc

Even with the reduced size and resolution of this short clip, you can probably see the intended effects.

  • Watch the disc. Describe what you see … do you see shapes? Colors?
  • As the rotation slows, do the shapes and colors change? How so?
  • If others are watching at the same time … compare what you see with what they see.
  • What does this do to the conventional wisdom that “seeing is believing”?
  • Where do the “rings” and “colors” exist? (They’re ‘manufactured’ by your nervous system.)
  • This suggests that “color is in the eye of the beholder.” What does this imply for all adjectives and descriptions?
  • View more visual misperception demonstrations by neurobiologist Christof Koch here.

Here is a visual explanation for the effect by Blue Man Group, from “Inside the Tube”:

Here is a basic explanation for the effect:

Here is another: