diopter

(dī äptər)

or dioptre

noun

a unit of measure of the power of a lens, equal to the power of a lens with a focal length of one meter

Origin: Fr dioptre < L dioptra < Gr instrument for leveling, etc. < dia-, through + base of opsis, sight < ops, eye

Related Forms:

See diopter in American Heritage Dictionary 4

noun Abbr. D.
A unit of measurement of the refractive power of lenses equal to the reciprocal of the focal length measured in meters.

Origin:

Origin: Obsolete diopter, an instrument for measuring angles

Origin: , from Latin dioptra

Origin: , from Greek dioptrā

Origin: : dia-, dia-

Origin: + optos, visible; see okw- in Indo-European roots

.

Related Forms:

  • di·opˈtral (-trəl) adjective

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