411 REFERENCE · Wiktionary
Cornsweet illusion
Reference material by Wiktionary contributors. This retains its source identity and is not 411 news reporting.
English
right|thumb|250px|Cornsweet illusion. The left part of the picture seems to be darker than the right one, though in fact they have the same brightness.
Etymology
It was described in detail by Tom N. Cornsweet in the late 1960s.
Noun
An optical illusion where an edge between regions of the same shade causes them to be perceived as different shades.
en eponyms
en Optical illusions