diopter

[ dahy-op-ter ]

Phonetic (Standard)IPA

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. : 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.

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Other Words From

di·optral adjective

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Word History and Origins

Origin of diopter¹

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

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Example Sentences

A split-focus diopter is implemented, one of a few homages to De Palma’s Body Double.

From Fortune

The unit of power employed by spectacle-makers is termed the diopter or dioptric (see Spectacles).

From Project Gutenberg

Diopter, the unit in terms of which the power of a lens or curved mirror can be expressed.

From Project Gutenberg

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dioptase dioptometer

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