The Notch Illusion

It’s optical illusion time again, and this time it is the Notch Illusion. Now I will admit I don’t think that is the actual name of this illusion, but I couldn’t find what it is really called so I just went with that. Ok, look at the image below and tell me if you see a straight chequered pattern or a wavy one.

The vast majority of people see a wavy pattern, when in fact the chequered pattern is arranged in nice neat straight lines. If you don’t believe me hold something straight up to the screen and see for yourself. So what gives?

Well, it is all down to those little notches at the corners of the squares. When we look at them our brains get confused and think that the larger squares must be slightly tilted. This in turn messes with our depth perception, tricking our brains into thinking that some of the corners are closer to us than others, causing us to see the pattern as wavy, as though something were bulging out of the pattern at various spots.

So I know what you are thinking, you’re thinking “how do I make one of my own”? You were thinking that right? Well here’s how. The image is made up of a repeating pattern of eight slightly different shaped blocks. Each line of the pattern is offset from the one above by one square. By simply repeating this pattern over and over you end up with the wavy chequered pattern seen above. I have a real urge to tile my kitchen floor like this.