Optical Wonderful
Motion Illusions
Static images that appear to shift, ripple, or spin, and the way the visual system's motion detectors can be tricked by nothing more than color, contrast, and pattern repetition.
Barber Pole Illusion
Stripes on a barber's pole seem to climb forever, though the pole only turns. The aperture problem, demonstrated with two windows of different shapes.
Motion
Motion Aftereffect (Waterfall Illusion)
Watch a turning spiral for 30 seconds and a still one seems to move the other way. Time how long your own waterfall illusion lasts and compare with other visitors.
Motion
Peripheral Drift Illusion
Still patterns that seem to creep out of the corner of your eye. Switch the brightness ramp to symmetric in the demo and the drift stops.
Motion
Rotating Snakes Illusion
Kitaoka's still image of rings that seem to turn on their own. Toggle the colours and the brightness order to find out what drives it.
MotionSpinning Dancer Illusion
A silhouette that some people see turning clockwise and others anticlockwise. Ours is filmed level, so the usual bias should vanish. Vote and see if it does.