diopter

(noun)

a unit of measure of the power of a lens or mirror, equal to the reciprocal of its focal length in meters. Myopia is diagnosed and measured in diopters

Related Terms

Examples of diopter in the following topics:

  • The Magnifying Glass

    • Typical magnifying glasses have a focal length of 25cm and an optical power of four diopters.

  • The Lensmaker's Equation

    • If the focal length is in meters, this gives the optical power in diopters (inverse meters).