Question 1089: CCD's eye candy!

The above figure is an illusion first described by X. The illusion's effect was first seen by a chap in X's lab and its name is the same as the place it was first observed by the said chap.

Id X and the name of the illusion.

Answer: X- Richard Gregory. The observant chap in his lab was Steve Simpson who first observed it on the wall of a cafe in Bristol, hence called the Cafe Wall illusion