We love a good optical illusion here at Creative Bloq, and even more so when it’s one that leaves people’s heads spinning like this one Can there really be 16 circles in the image below? There are, but people are struggling to find them.

Known as the coffer illusion, this piece of visual trickery was discovered by accident by the Stanford University psychologist and vision scientist Anthony Norcia almost two decades ago. And it continues to baffle people today.