Eyeball Bender

Just spotted this on Boing Boing. I stared at it for a long time and it didn't change direction. Then I stared at it for a bit longer and still it didn't change direction. I read the instructions and looked at it again and it still didn't change direction. Then, I looked away for a second, and then I looked back and all of the sudden it had changed direction! I managed to get it to flip a couple of times but it's really strange and freaky. Enjoy.