The most stunnning illusion EVER

I am sure we have all seen numerous illusions but this one so darn stunning that I literally let out a shriek seeing this one.

Look at squares A and B. They are the same shade of gray. I am sure you wont believe this, I didn't, well take a printout, cut it into 4 pieces, take the squares A & B side by side and see for yourself. Lazier ones can use mspaint/gimp to see the magic.

Brightness and color can have powerful effects on perception. In this illusion created by vision scientist Edward H. Adelson of the Massachusetts Institute of Technology. Our brain does not perceive the true brightness and color of each square but instead determines the brightness and color of A and B by comparison with the squares surrounding them