Content - Floating Patterns
Do this first:
Move your head about as you look at the pattern. Even better, let your head roll - you'll survive!
Click on the pattern and drag it slowly from side to side.
What's going on?
It is known that regular, contrast-rich areas can invoke visual instability or even colours, where there aren't any. Have a look at the rotating disks in the sector Light & Vision.
To get a floating pattern it is necessary that the chessboard pattern is distorted lengthways on the disk as well as on the ring. Such elements with clear borders seem to be important to make the floating and disuniting from each other possible. Patterns with stripes only won't work.
By moving the whole pattern, larger zones of conjugated elements with the same direction detach visually from the others.
It is not completely understood how this illusion is possible.