The Coffer Illusion - how many circles do you see?
by Mark Frauenfelder from on (#2Y2W1)
Relatively interesting has three good optical illusions in this post. My favorite is the Coffer Illusion, which was a Top 10 finalist in the 2006 Best Illusion of the Year Contest, but is new to me. Do to see all 16 circles? For me, it took a while.