diopter
[ dahy-op-ter ]
/ daɪˈɒp tər /
noun
Optics.
a unit of measure of the refractive power of a lens, having the dimension of the reciprocal of length and a unit equal to the reciprocal of one meter. Abbreviation: D
an instrument, invented by Hipparchus, to measure the apparent diameter of the sun or moon or to estimate the size or elevation of distant objects.
Also
especially British,
di·op·tre.
Origin of diopter
1585–95; < Latin
dioptra < Greek: instrument for measuring height or levels, equivalent to
di-
di-3 +
op- (for
ópsesthai to see) +
-tra noun suffix of means
OTHER WORDS FROM diopter
di·op·tral, adjectiveWords nearby diopter
Example sentences from the Web for diopter
Diopter, the unit in terms of which the power of a lens or curved mirror can be expressed.
The New Gresham Encyclopedia |VariousThe unit of power employed by spectacle-makers is termed the diopter or dioptric (see Spectacles).
Medical definitions for diopter
diopter
[ dī-ŏp′tər ]
n.
A unit of measurement of the refractive power of lenses equal to the reciprocal of the focal length measured in meters.