Shine on, you crazy diamonds

This optical illusion tripped me out. I watched it several times, and eventually I resorted to holding fingers up over the screen convincing myself that what happened was real.

If you look really closely (and once you know it, it’s easier to see) the diamonds are not actually solid colour. Each diamond is a gradient — slightly darker on the bottom, slightly lighter up top — and your eye makes adjustments that make them seem solid.

I kept hoping that the guy in the video would turn the one diamond upside-down, to break the illusion, but he never did.

Here’s another, similar one:

Crazy, hey? These are both embedded on this, Spanish, site. But I was pointed in their direction via BoingBoing.