TypeMotion
InteractiveYes: sliders and a check
First described2000
Look at the red cross. As the picture zooms, the rings seem to rotate, one each way.
Try this
- Keep your eyes on the center.
- Tick Stop zooming: no zoom, no rotation.
- On a phone, try turning off zoom and moving the screen toward and away from your face instead.
Why it happens
Baingio Pinna and Gavin Brelstaff described it in 2000 as a new illusion of relative motion. Each square has a light edge on two sides and a dark edge on the others. As the image grows or shrinks, the edges move outward; motion-sensing neurons that only see a small piece of each edge read the motion as partly sideways, and the ring seems to turn.
Did you know?
The original version works by moving your head toward and away from a printed page.
References
- Pinna B., Brelstaff G. (2000). A new visual illusion of relative motion. Vision Research, 40, 2091-2096. doi:10.1016/s0042-6989(00)00072-9
- Background on Wikipedia
The illusion on this page is drawn by code written for this site. Last checked 1 November 2026.
Frequently asked questions
Why do the Pinna-Brelstaff rings rotate?
Motion detectors see each tilted edge moving partly sideways as the image expands, so the ring seems to turn.
