Café Wall Optical Illusion
The café wall illusion is a classic optical illusion that is among of of the first images one would think of when you talk about optical illusions. Discovered first in 1973 when view the tiles outside a café in Bristol. There of the name, Café wall illusion.
The café wall illusions was noticed by a laboratory worker called Steve Simpson but was made known to the public as an optical illusion by Richard Gregory.
You can stare at this optical illusion for hours, but it's not until you compare the grey lines with a piece of paper you will really see that lines truly are straight. The white and dark bricks unevenly placed make your eyes see these wavy lines.
The Café Wall
At google you can find many pictures of the original café wall and also see how the café wall looks today in Google Street View
A great picture on Flickr or the café wall optical illusion