Maybe you know that faces are more difficult to recognize when they’re upside-down and that sometimes we misperceived the facial expressions of upside-down faces .
But Peter Thompson , from the University of York (UK) discovered an amazing optical illusion !
We can name it The Fat Face Thin illusion. Your assignment is to compare the upside-down face on the left of the lower figure with the upright face on the right. Have you noticed how the upside-down version looks much thinner?! Moreover it appears longer shaped than the upright version. Of course, there is no need to mention how both pictures are identical. This illusion illustrates the internal features of the face (eyes, nose, mouth) can distort our perception of face shape.