dioptre

dioptre US, diopter [daɪˈɒptə]

n

(Mathematics & Measurements / Units) a unit for measuring the refractive power of a lens: the reciprocal of the focal length of the lens expressed in metres

[from Latin dioptra optical instrument, from Greek, from dia- through + opsesthai to see]

dioptral  adj

Thesaurus

Noun

1.

dioptre - a unit of measurement of the refractive power of a lens which is equal to the reciprocal of the focal length measured in meters; used by oculists diopter unit, unit of measurement - any division of quantity accepted as a standard of measurement or exchange; "the dollar is the United States unit of currency"; "a unit of wheat is a bushel"; "change per unit volume"

Translations

dioptre, (US) diopter

n → Dioptrie f