Once you see it, you’ll kick yourself. But this deceptively simple optical illusion is frustrating and confusing people across Facebook. All it asks is to spot anything unusual in the photograph of a brick wall.

The image was uploaded by Facebook user Arron Bevin along with the caption: “This is one of the best optical illusions Iv [sic] seen… Took me a good 5 minutes.”

If you can’t see anything, you won’t be alone. Most of the commenters seem to be equally confused as to what they’re looking for, with some of the top rated commenters saying: “I'm done looking... There's nothing there” and “There's nothing there I give up.”

Give the image below a click to reveal the answer.