café wall illusion

See also: café-wall illusion

English

Alternative forms

• café-wall illusion

Etymology

Described under its current name in 1973 by Richard Gregory, according to whom this effect was observed by a member of his laboratory, Steve Simpson, in the tiles of the wall of a café at the bottom of St Michael’s Hill, Bristol.

Noun

café wall illusion (plural café wall illusions)

The café wall illusion. The horizontal lines are parallel, despite appearing to be at different angles to each other.

1. An optical illusion in which the parallel straight dividing lines between staggered rows with alternating dark and light bricks appear to be sloped rather than parallel.

Further reading

• café wall illusion on Wikipedia.Wikipedia