There are numerous variations on “spot the difference.” Many painters, illustrators, and photographers have risen to the challenge of subtly altering an image. It’s similar to meeting identical twins!

They appear identical at first glance, but the closer you look — and the keener your eyes — the more subtle the distinctions become. How quickly do you discover the differences in these portraits?

From helping you relax and unwind to training you to recognize and analyze the smallest of details, puzzles have been all around us for our entertainment for centuries.