Fun with Clowns
Can you make one clown in the middle by crossing your eyes? The clown should have a hat and a red nose. Is there a plus sign in the circles below the clown? If the hat, nose or one of the lines in the plus sign tries to disapear, it means your visual system is working so hard that your brain is trying to shut off an eye. Blink a couple of times to see if the picture comes back.