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diopter

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noun di·op·ter \dī-ˈäp-tər, ˈdī-ˌäp-\

Definition of diopter

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



Origin and Etymology of diopter

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


Medical Dictionary

diopter

noun di·op·ter

Medical Definition of diopter

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



Variants of diopter

or chiefly British

dioptre

\dī-ˈäp-tər, ˈdī-ˌäp-\play

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