diopter

noun

di·​op·​ter dī-ˈäp-tər 

ˈdī-ˌäp-

: a unit of measurement of the refractive power of lenses equal to the reciprocal of the focal length in meters

Examples of diopter in a Sentence

Recent Examples on the Web

The diopter adjustments worked perfectly, and the text and other interface elements on both my phone and Switch 2 came through razor-sharp. — Will Greenwald, PC Magazine, 6 Aug. 2026

There are some beautiful split-diopter shots, and the period soundtrack — Ultravox, Fleetwood Mac, Peter Gabriel, Blondie — is banging. — Roxana Hadadi, Vulture, 5 Aug. 2026

In addition, the goggles can be adjusted to fit the operator’s interpupillary distance, while the diopters can be tuned for users requiring prescription lenses. — David Szondy may 17, New Atlas, 17 May 2026

Old fashioned filmic techniques like split diopter shots, iris wipes, and chiaroscuro lighting add another layer of maximalist flare to the whole affair. — Marya E. Gates, IndieWire, 9 Sep. 2025

Word History

Etymology

diopter (an optical instrument), from Middle French dioptre, from Latin dioptra, from Greek, from dia- + opsesthai to be going to see — more at optic

First Known Use

circa 1864, in the meaning defined above

Medical Definition

diopter

noun

di·​op·​ter

variants or chiefly British dioptre

dī-ˈäp-tər, ˈdī-ˌäp- 

: a unit of measurement of the refractive power of a lens equal to the reciprocal of the focal length in meters