barber pole illusion

English

The grating is actually drifting downwards and to the right at 45 degrees, but its motion is captured by the elongated axis of the aperture.

Alternative forms

• barber-pole illusion, barberpole illusion

Noun

barber pole illusion (plural barber pole illusions)

1. An optical illusion where, when a diagonally striped pole is rotated around its vertical axis (horizontally), it appears as though the stripes are moving in the direction of its vertical axis (downwards in the case of the animation to the right) rather than around it.

Synonyms

• barber pole effect