11 Faces Optical Puzzle

How many of the faces in this optical puzzle can you find? Hint: people here have actually found several more than 11 though a few are debatable... if you see more than 20, you have probably been staring at this too long and you are hallucinating... ;-)

When you have either given up or think you've found them all, look at a copy that shows the ones we've found... Don't cheat and look too early!

If you liked this puzzle, try 9 People Optical Puzzle