love these!

I love optical illusions! 

 This guy is wearing board shorts that are black and white. 

 this is one of those where the lines are actually straight across, not crooked.

this one practically broke the internet! below is the reveal...

 This isn't really an illusion, but more of a, what's wrong with this picture. If you can't figure it out, I put the answer in the comments.

 Are these craters or sand dunes?? The correct answer is sand dunes.

Basically, your brain thought the sun was in the 1:00 position, casting shadows from the upper right. However, the sun was actually casting shadows from the upper left. If you look at the photo upside down, the illusion disappears. Isn't that crazy!?

 you know this one...both of the monsters are the same size.

This one is neat because it's not really a spiral. They're really concentric circles! Whoa.

The blue and the green background are the same color.

This one makes my head hurt and my eyes water.