Main Entry: Stiles–Craw·ford effect

Pronunciation: \ˌstīlz-ˈkrȯ-fərd-\

Function: noun

: an optical phenomenon in which light passing through the center of the pupil is perceived as more intense than light passing through the periphery of the pupil

Stiles, Walter Stanley (1901–1985), and Crawford, Brian Hewson (1906–1991), British physicists. Stiles spent almost all of his career as a research scientist at the National Physical Laboratory in Great Britain. He was the author of numerous papers on illuminating engineering and physiological optics. He published book-length studies on thermionic emission (1932), the science of color (1967), and the mechanisms of color vision (1978). The Stiles-Crawford effect honors their names.