This is one of the coolest optical illusions I’ve stumbled upon in recent memory, it just works so well! As you follow the arrows the circles appear to move in the same direction. They also appear to expand and contract in size, but of course it’s all an optical illusion and the circles never move or change size.

If you don’t believe it, try blinking really fast while staring at the image and you will see the circles never move or change in size. Awesome!!!