Time to twist your brain again. Here’s an optical illusion which is really hard to believe. Check out the colors in the box A and box B. What do you think about them? Now here comes the fun…would you actually believe that they both have the same color as background??

Obviously you think we are nuts. But we are not. The next picture will explain you why.

This is called Adelson’s checker shadow illusion originally published by Edward H. Adelson, Professor of Vision Science at MIT in 1995.

[source: en.wikipedia.org]