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a unit of refractive power of lenses: the reciprocal of the focal length in meters is the refractive power in diopters. Symbol D.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

di·op·ter (D),

The unit of refracting power of lenses, denoting the reciprocal of the focal length expressed in meters.
[G. dioptra, a leveling instrument]
Farlex Partner Medical Dictionary © Farlex 2012


(D, Δ, δ) (dī-op'tĕr)
The unit of refracting power of lenses, denoting the reciprocal of the focal length expressed in meters.
[G. dioptra, a leveling instrument]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

Diopter (D)

Unit describing the amount of focusing power of a lens.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Self-imaging the eye was performed successfully using a smartphone and 90 Diopter lens while facing a mirror.
Refraction: Mean of refractive spherical equivalent from -3.40 diopters before operation got to -0.080.4 diopters 5 years after operation (in the range of -1.25 to 1.75 diopters) (Fig.1) (Table-II).
The conventional center-focusing dial and right-eyepiece diopter adjustment add to its ease of use.
With the introduction of the Tilos Hawk Eyes Scuba Diving Masks, Seavenger now features prescription lens choices in bi-focal diopters, in addition to the existing variety of different masks currently offered from premier dive manufacturer IST Sports.
It has a 20mm objective, fully-coated optics and a 4X eyepiece with adjustable diopter to provide bright, crisp images at any distance.
Sig Sauer, a leader in commercial, law enforcement, and military firearms manufacture, has introduced a rotary diopter sight system that is optimized for the SIG 556 rifle and provides serious shooters with a high-quality set of iron sights with CQB capabilities.
Other features include dielectric-coated prisms for enhanced resolution, dual-focus knob with locking diopter adjustments, and horn-shaped detachable eyecups.
These safety glasses come in clear and smoke, and feature a magnification diopter molded into the polycarbonate lens to combine safety glasses with reading glasses.
First I measured my degree of nocturnal myopia, which turned out to be -0.75 diopter in both eyes.
The large free-standing focus wheel contains an easily readable locking click-stop precision diopter control, which is easy to manipulate even when wearing heavy gloves and requires only slightly more than one complete revolution to adjust from infinity to the closest focus point (as close as 9.7 feet).
The long eye relief includes an adjustable, 6X diopter. The rangefinder operates on a CR2 lithium battery and comes with a Realtree APG neoprene case and two-year warranty.