Can you find the circles hidden in this picture?

Remember those posters you would stare at forever trying to find the sailboat or unicorn or whatever shape was hidden in the frame? Well, we’ve got another one for you. The Coffer Illusion—which has been making the rounds on Facebook—has everyone questioning the sanity of the person who first created it and posed the question: How many circles are there really?

Because: wait. Circles? Are you out of your mind?

Take a look at the image in question:

At first glance, this would appear to be just a bunch of black and white lines and squares. But no. There are actually 16 circles in this photo. Can you spot them? I’ll give you a second to stare at it.

Or a minute.

Or an hour.

As one commenter on the photo said, “Once you see them, you can’t unsee them.” Still can’t find them? I’ll give you a hint: Look between the rectangles…

Ohhhhhhhh…

And the CIRCLE GETS THE SQUARE!

The person who posted the puzzle, Nicholas Johnson, is actually a magician and entertainer who also educates children on the science of deception and the mind. He said it took him 30 minutes to find the circles. His post has since been shared about 10,000 times by some people who were equally confounded, and others who thought Johnson was a blind moron.

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This particular illusion has been so omnipresent online lately that even Today did a feature on it.

The Coffer Illusion, named after the architectural term “coffer,” was created by Anthony Norcia of The Infant Vision Laboratory at Smith-Kettlewell. The illusion works because of our brain’s tendency to want to see closed shapes, and because of its interpretation of the vertical versus the horizontal stripes.

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The illusion was actually a finalist for the 2006 Illusion of the Year. Yes, apparently there is such a thing as the illusion of the year.

Norcia apparently showed this illusion to 100 people, and it took them an average of 45 seconds to see it. How long did it take you?

via GIPHY

Want more optical illusions? See if you find the frog in this photo or the hidden faces in this one.