A dioptre (British spelling) or diopter (American spelling), symbol dpt or D, is a unit of measurement with dimension of reciprocal length, equivalent to one reciprocal metre, 1 dpt = 1 m−1.

Oct 30, 2022 · A diopter is a unit that is used to calculate the focusing strength of a pair of glasses or contact lenses. It is the unit used for an optical prescription.

Dec 8, 2025 · The diopter is the standard unit of measurement used to quantify the optical power of a lens or curved mirror, which measures its ability to bend or refract light rays.

Apr 4, 2024 · The basic unit of measurement in optometry, diopters, is used to express the optical power of prescription lenses. They are made expressly to gauge the way a lens bends or refracts light to …

Sep 10, 2024 · A diopter is a unit of measurement for a lens’s focusing power. Learn more about what a diopter measures and how diopters vary by prescription.

May 21, 2024 · One diopter (D) is equivalent to the reciprocal of the lens's focal length in meters. A lens with a power of 1 diopter (1D) indicates that light rays passing through it will either converge or …

Feb 10, 2025 · A diopter is a unit that measures the refractive power of a lens or an optical system, describing how effectively it bends light to focus an image on the retina.

diopter, in optics, unit of magnifying power of a lens or lens system. Because the power of a lens is proportional to unity (one) divided by the focal length (see lens), the power of a lens in diopters is …

Diopter strength refers to the optical power of a lens. It's commonly applied to reader-strength eyeglasses or bifocals, as well as telescopes & other magnifying lenses.

A diopter is the unit of measurement used to describe the optical power of a lens. A diopter shows what level of lens curve is required to aim light satisfactorily to your retina.