This is a Visual Selective Attention experiment conducted by Becklen and Cervone(1983) to show that the human mind has its limits. Please focus really well to see how you can be decieved.
This very simple video shows that that you can create a visual illusion in your garage. With all respect to Charlie Chaplin, his face is used to show a 3d optical illusion where his head is turned and you sort of see two faces at the same time. See the video if you don’t believe …