
The Spinning Silhouette Optical Illusion
For me the switch didn't just happen - I had to look at her shadow and picture it going counter-clockwise. After about a minute, my brain flipped and the lady just started spinning backwards. Actually - I can't seem to convince my brain to get her to start going clockwise again. But it is pretty wild when you see the switch happen.
This spinning illusion has also been referred to as a Right Brain vs. The Left Brain challenge.
It's a tough one and it takes a lot of focus.