diopter
nounEtymology From Latin dioptra, from Ancient Greek διόπτρα (dióptra).
8 senses
- 1A unit of measure of the power of a lens or mirror…
- 2The dioptre adjustment mechanism of a pair of binoculars…
- 3A lens element attached to the front of a photographic…
- 4Any lens system, such as a telescope.
- 5A theodolite or similar surveyor’s angle measuring device.
- 6An alidade.
- 7A surgical speculum.
- 8An instrument for drawing the skull by projections.
1
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.
2
The dioptre adjustment mechanism of a pair of binoculars or of a camera viewfinder.
3
Arts, Hobbies, Lifestyle, Photography 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".
4
Obsolete Any lens system, such as a telescope.
5
Obsolete A theodolite or similar surveyor’s angle measuring device.
6
Obsolete An alidade.
7
Obsolete A surgical speculum.
8
Obsolete An instrument for drawing the skull by projections.