Found 2 items, similar to diopter.
English → English (WordNet) Definition: diopter 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
English → English (gcide) Definition: Diopter Diopter \Di*op"ter\, ||Dioptra \Di*op"tra\, n. [L. dioptra, fr. Gr. ?. See 2d Dioptric.] An optical instrument, invented by Hipparchus, for taking altitudes, leveling, etc. [1913 Webster] ||