释义 |
Definition of dioptre in English: dioptre(US diopter) noun dʌɪˈɒptədaɪˈɑptər A unit of refractive power, which is equal to the reciprocal of the focal length (in metres) of a given lens. vision corrected to within one dioptre of perfect sight Example sentencesExamples - The difference between the focusing powers of these two axes, measured in dioptres, is the astigmatism.
- Refractive error is measured in dioptres, and myopia is designated with a minus sign.
- The presence of 1 dioptre of refractive error reduces Snellen visual acuity to less than 6/12 that is, below the level needed to drive.
- For a typical 3-mm-diameter lens, the dioptric power can be controlled between - 100 and + 50 diopters.
- The focusing power of a lens is measured in dioptres.
Origin Late 16th century (originally as diopter, denoting an alidade): from French, from Latin dioptra, from Greek, from di- 'through' + optos 'visible'. The term was used in the early 17th century to denote an ancient form of theodolite; the current sense dates from the late 19th century. Definition of diopter in US English: diopternoundīˈäptərdaɪˈɑptər A unit of refractive power that is equal to the reciprocal of the focal length (in meters) of a given lens. vision corrected to within one diopter of perfect sight Example sentencesExamples - Refractive error is measured in dioptres, and myopia is designated with a minus sign.
- The difference between the focusing powers of these two axes, measured in dioptres, is the astigmatism.
- The presence of 1 dioptre of refractive error reduces Snellen visual acuity to less than 6/12 that is, below the level needed to drive.
- The focusing power of a lens is measured in dioptres.
- For a typical 3-mm-diameter lens, the dioptric power can be controlled between - 100 and + 50 diopters.
Origin Late 16th century (originally as diopter, denoting an alidade): from French, from Latin dioptra, from Greek, from di- ‘through’ + optos ‘visible’. The term was used in the early 17th century to denote an ancient form of theodolite; the current sense dates from the late 19th century. |