lilac chaser

An optical illusion involving 12 pink blurred discs arranged in a circle around a…An optical illusion involving 12 pink blurred discs arranged in a circle around a small black, central cross on a grey background. The brief disappearance of each disc in turn causes the observer to see a gap running around the circle of pink discs; a green disc running around the circle of pink discs in place of the gap; or the green disc running around on the grey background, with the pink discs having disappeared in sequence.