What's up with witch rings?

Perception. 2015;44(1):103-6. doi: 10.1068/p7865.

Abstract

'Witch rings' are well-known novelty rings that show a size-change illusion when rotated. We have replicated the illusion of expansion of the reflections in the rings in a variety of contexts with animations, though not as yet so successfully imitated the sense that the whole ring expands and contracts.

MeSH terms

  • Humans
  • Illusions / physiology*
  • Motion Perception / physiology*
  • Size Perception / physiology*