A new illusion from the great Japanese psychologist Akiyoshi Kitaoka. Notice the pinkish spots against the cyan background. But the image is constructed entirely of shades of cyan! What Prof. Kitaoka finds even more remarkable is that if you stare at the image for a while, and then look at a blank white wall, you would expect to see an afterimage with the complementary color to the one you stared at, but in this case the afterimage of the dots appears cyan! Try it.

Another recent illusion from Prof. Kitaoka. Notice the two trapezoidal boxes with red lids. In this nice variant of Shepard's illusion, the two box lids appear to be of very different size and shape. But if you trace one lid on a sheet of thin paper and move it over to the second, you'll see they're identical.