diopter en · NOUN
Pronunciation
- (Southern-England) audio
Etymology
From Latin dioptra, from Ancient Greek διόπτρα (dióptra).
Meanings
- A unit of measure of the power of a lens or mirror, equal to the reciprocal of its focal length in meters. Myopia is diagnosed and measured in diopters.
- The dioptre adjustment mechanism of a pair of binoculars or of a camera viewfinder.
- (dated) A lens element attached to the front of a photographic lens to shorten the lens's minimum focus distance; also called a "close-up filter".
- (obsolete) Any lens system, such as a telescope.
- (obsolete) A theodolite or similar surveyor’s angle measuring device.
- (obsolete) An alidade.
- (obsolete) A surgical speculum.
- (obsolete) An instrument for drawing the skull by projections.
Forms
| Spelling | Features | Labels | Source |
|---|---|---|---|
| diopters | Number=Plur | lexicographic | |
| dioptry | alternative | lexicographic | |
| dioptre | alternative | lexicographic | |
| dioptra | alternative | lexicographic |
Translations (18)
it diottria (unit of measure) · fi diopteri (unit of measure) · de Diopter (lens system) · mk диоптер (unit of measure) · fi teodoliitti (theodolite) · de Diopter (theodolite) · es dioptría (unit of measure) · pl dioptria (unit of measure) · fi dioptria (unit of measure) · mk диоптрија (unit of measure) · ja ディオプトリ (unit of measure) · ru дио́птрия (unit of measure) · pt dioptria (unit of measure) · hu dioptria (unit of measure) · de Dioptrie (unit of measure) · cs dioptrie (unit of measure) · eu dioptria (unit of measure) · ca diòptria (unit of measure)