The Thatcher Illusion

23 Sep 2007

Want to see something cool?

Thatcher Illusion

Aside from upside down, pretty normal, right? Compare it to these:

Thatcher Illusion

What the heck happened here, and why does the left photo look like something you'd find on the pages of Fark? Consider this: the two pairs of photos are exactly the same, except rotated 180 degrees.

This is the best example of the Thatcher Illusion, an optical illusion I stumbled upon this weekend. People don't tend to recognize faces holistically; rather, we focus on local features like the eyes or mouth. As a result, if you invert the photo but leave the eyes rotated "normally", it looks fine. But do the inverse and you've midwived a monstrosity. You can see more examples (including a polarity-reversed photo of Tony Blair) here.

This reminds me of my favorite facial optical illusion: