Optical illusions are always fascinating. This one is particularly interesting. What you sees here, is a few pink (or purple) spots on a grey background. But when you focus on the cross in the middle, you'll really get a surprise.
Did you see it? The spots turn green for a short time. And if you look for longer, they disappear altogether. Share this fascinating illusion with your friends. You could even bet that the spots are green - and be sure to win!
