Optical Illusion: "Rotating Lady"

I have already posted on this matter in several other blogs, but I will go ahead and copy my words here as well. If you don't know what the above is, it's an optical illusion of a rotating silhouette. Dependent upon how you look at it, she can be rotating clockwise or counter-clockwise.

Having a tendency towards skepticism, I initially believed this to be a fake. It is not-- it is a very real optical illusion.

Download a free animation editor and you will see that 17 frames are dedicated to the left side, and 17 frames are dedicated to the right. The animation is looped, not reversed.

Focus on the first frame and imagine that her back is facing towards you. Slowly direct your way through each frame. She will appear to move in a clockwise motion.

Now do it again. Focus on the first frame and imagine her front is facing towards you. She will appear to move in a counter-clockwise motion.