Escher-like optical illusions are not always so complicated as the one above. Try the more simple but even so effective climbing the stairs as shown below. It's deceptive how the trick is done but look closely to the tiles and the way the painting is drawn. To make such an optical illusion, the artist has to step back from his work of art and see if the perspective is still right. DO try this at home !!
(source: stumbleupon.com)
