Indie-Resource.com

http://www.dailymail.co.uk/sciencetech/ ... -them.html

They both go the same direction. It's the moving black-white gradient that f's with your mind as we are geared up to relate movements by shadows. Thanks for the headache

I'm blind now!

Yep! If you look away from it (like right above the image so you are seeing it out of the corner-ish of your eye), after a moment it suddenly starts turning the other direction. Very nice!

Brusspup on YouTube comes up with some very nice illusions and cool science stuff