Definitions

from The American Heritage® Dictionary of the English Language, 5th Edition.

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

from The Century Dictionary.

  • noun An ancient form of theodolite.
  • noun The alidade or index arm of a graduated circle.
  • noun An instrument used in craniometry for obtaining projections of the skull.
  • noun A dioptric.

from the GNU version of the Collaborative International Dictionary of English.

  • noun An optical instrument, invented by Hipparchus, for taking altitudes, leveling, etc.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • 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.
  • noun obsolete Any lens system, such as a telescope.
  • noun obsolete A theodolite or similar surveyor’s angle measuring device.
  • noun obsolete An alidade.
  • noun obsolete A surgical speculum.
  • noun obsolete An instrument for drawing the skull by projections.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun a unit of measurement of the refractive power of a lens which is equal to the reciprocal of the focal length measured in meters; used by oculists

Etymologies

from The American Heritage® Dictionary of the English Language, 4th Edition

[Obsolete diopter, an instrument for measuring angles, from Latin dioptra, from Greek dioptrā : dia-, dia- + optos, visible; see okw- in Indo-European roots.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

From French dioptre, from Latin dioptra, from Greek διοπτρα ("to see through").

Examples

  • A diopter is a unit of measurement that indicates the amount of correction needed to change your vision to be as close to 20/20 as possible.

    Eyeglasses 101

  • The diopter is a little adjustment that you can make to how your viewfinder works - it's particularly useful for people with poor eye sight - it's usually a little wheel next to your viewfinder.

    xml's Blinklist.com

  • The diopter is a little adjustment that you can make to how your viewfinder works - it's particularly useful for people with poor eye sight - it's usually a little wheel next to your viewfinder.

    xml's Blinklist.com

  • The diopter is a little adjustment that you can make to how your viewfinder works - it's particularly useful for people with poor eye sight - it's usually a little wheel next to your viewfinder.

    xml's Blinklist.com

  • Also connected with this is checking the 'diopter' on your camera (if it has one.

    xml's Blinklist.com

  • Also connected with this is checking the 'diopter' on your camera (if it has one.

    xml's Blinklist.com

  • Even the best (read extravagantly expensive) binocular on the market will give you a fuzzy view of the world until you correctly set the diopter ring.

    Focus Your Binoculars by Adjusting the Diopter

  • Adjusting the diopter the right way makes all the difference.

    Focus Your Binoculars by Adjusting the Diopter

  • Look at the same object, and turn the diopter ring (see inset) to bring the object into sharp focus.

    Focus Your Binoculars by Adjusting the Diopter

  • Well, after archery today (I shot pretty well for somebody who is probably a quarter of a diopter off in the prescription for her dominant eye, currently) and dinner, I went after the poor shedding GRD with an undercoat rake.

    skin as white as a cuttlefish bone

Comments

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  • (n): in optics and cinematography, part of the lens or viewfinding system that can be adjusted to compensate for one's own particular eyesight, allowing one to see the groundglass clearly.

    January 18, 2009