diopter : Dictionary / Wörterbuch (BEOLINGUS, TU Chemnitz)

English Dictionary: diopter	by the DICT Development Group
2 results for diopter
From WordNet (r) 3.0 (2006) [wn]:
diopter n 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 Synonym(s): diopter, dioptre
From Webster's Revised Unabridged Dictionary (1913) [web1913]:
Diopter \Diop"ter\, d8Dioptra \[d8]Diop"tra\, n. [L. dioptra, fr. Gr. [?]. See 2d {Dioptric}.] An optical instrument, invented by Hipparchus, for taking altitudes, leveling, etc.