Stare at the black star while covering your right eye. Come closer to the screen and watch as the colored star disappears. Amazing! it disappears as if by magic.
An optical illusion is tricking your mind into thinking something disappears, or something moves. It tricks your mind into thinking its something else. I did mine by making a colored star. Then i made another star that had the outline of black. Then you just move in closer to the screen covering your right eye. It shows that your eye has a blind spot.