We love a good trick of the eye here at Creative Bloq. Our pick of the best optical illusions includes everything from Super Mario confusing us on a staircase to a spinning horse. But some mind benders still just leave me stumped, and this is one of them.

The checker shadow illusion is a famous optical illusion that’s been intriguing scientists for years. But I have to admit that I suspected a fast one when I first came across it. We’re told that Square A and square B in the illustration below are exactly the same shade of grey. How can that be?