2008 Third prize
The well-known hollow-mask illusion: hollow masks appear as normal faces that “follow” viewers who move in front of them. Also, when a hollow mask rotates on a turntable, it appears to turn opposite to the actual direction of the turntable.
An interesting variant: If we add 3-D objects to the mask (e.g., a cigarette) or attach 3-D eyeballs on the whites of the eyes, what will the percept be when we turn the mask? Answer: The result is a compelling illusion in its own right; these objects appear to rotate in the opposite direction to that of the mask.
See a longer version of the video
Read more about the illusion and possible explanations
Rolling Eyes on a Hollow Mask,
