An optical illusion where identical arcs stretch and shrink.
It’s probably the world’s most baffling optical illusion. Hold one arc above the other and ask the question, “Which arc is bigger?” The bottom arc will always look bigger than the top one, yet they are actually the same size! Reverse the arcs to make the other one look bigger. What you see is not always what you get! Keep reading and we’ll let you in on some presentation ideas and stunts that will really amaze and fool your friends.