PURPLE NURPLE: This purple swirl seems to move eerily, but it's actually a static image. As with other illusions of this type, the motion seems greatest in your peripheral vision.
COUNT THE INVISIBLE BEARS: This fellow may appear to be all alone, but he's on the run from wild animals. Can you guess how many creatures are hidden in the landscape?
DALI!: Here's a clever art installation created by Salvador Dali. From this angle it's hard to tell what you're looking at.
DESKTOP DELUSION: This simple sketch seems somehow to jump off the page. It's drawn in forced perspective, giving it the appearance of a three-dimensional object when viewed from this angle.
(All images courtesy of Mighty Optical Illusions.)