Illusion Wizzard
Cafe wall illusion
The cafe wall illusion is an optical illusion, first described by Richard Gregory in 1973. According to Gregory, this effect was first observed by a member of his laboratory, Steve Simpson, in the tiles of the wall of a cafe at the bottom of St Michael's Hill, Bristol.
This optical illusion makes the parallel straight horizontal lines appear to be bent.
To construct the illusion, alternating light and dark "bricks" are laid in staggered rows. It is essential for the illusion that each "brick" is surrounded by a layer of "mortar" (the grey in the image). This should ideally be of a colour in between the dark and light colour of the "bricks".
Submenu: Optical Illusions
