diopter

We have found lemma(root) word of diopter : dioptre.

Definitions


[dʌɪˈɒptə], (Noun)

Definitions:
- a unit of refractive power, which is equal to the reciprocal of the focal length (in metres) of a given lens
(e.g: vision corrected to within one dioptre of perfect sight)


Phrases:

Origin:
late 16th century (originally as diopter, denoting an alidade): from French, from Latin dioptra, from Greek, from di- ‘through’ + optos ‘visible’. The term was used in the early 17th century to denote an ancient form of theodolite; the current sense dates from the late 19th century




definition by Oxford Dictionaries