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Related to binocularly: monocular, binoculars


small optical instrument consisting of two similar telescopestelescope,
traditionally, a system of lenses, mirrors, or both, used to gather light from a distant object and form an image of it. Traditional optical telescopes, which are the subject of this article, also are used to magnify objects on earth and in astronomy; other types of
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 mounted on a single frame so that separate images enter each of the viewer's eyes. As with a single telescope, distant objects appear magnified, but the binocular has the additional advantage that it substantially increases the range of depth perception of the viewer because the magnified images are seen with both eyes. The frame of a binocular is usually hinged to permit adjustment of the distance between the telescopes. Focusing can be done by means of a wheel on the central axis between the telescopes; turning the wheel changes the distance from the objective lenses of the telescopes to the eyepieces. Separate focusing of each telescope from the eyepiece may be provided in some types of binocular. The term binocular now usually refers to the prism binocular, in which light entering each telescope through its objective lens is bent first one way and then the other by a pair of prisms before passing through one or more additional lenses in the eyepiece. The prisms aid in reducing the length of the instrument and in enhancing the viewer's depth perception by increasing the distance between the objective lenses. Other types of binocular include the opera glass and the field glass; both use Galilean telescopes, which do not employ prisms and which usually have less magnifying power than the telescopes in prism binoculars. A binocular is often specified by an expression such as "7×35" or "8×50"—the first number indicates how many times the binocular magnifies an object and the second number is the diameter of either objective lens in millimeters. The size of an objective lens is a measure of how much light it can gather for effective viewing.


See J. T. Kozak, Deep-Sky Objects for Binoculars (1988).


Of, pertaining to, or used by both eyes.
Of a type of visual perception which provides depth-of-field focus due to angular difference between the two retinal images.
Any optical instrument designed for use with both eyes to give enhanced views of distant objects, whose distinguishing performance feature is the depth perception obtainable.
References in periodicals archive ?
This P training involved repetitive and systematic alternation of the flippers every 15 to 20 s monocularly and binocularly, without any spherical lens power changes (i.
The Farnsworth test, which consists of color caps that are more vivid than those of the Lanthony test, was completed binocularly first.
Problem Age 3 Vision 6/24 (20/80) binocularly with Cardiff cards (equivalent to seeing at 6 meters what typically sighted individuals see at 24 meters).
Rapid eye movements (REMs) : Dement and Kleitman (2) described the eye movements occurring during REM sleep as binocularly synchronous and apparently similar to waking fixational eye movements occurring with similar velocities in all directions.
40) VT to stabilise and improve accommodation, pursuits and saccades can be performed with standard VT techniques, first monocularly and then binocularly.
If the patient saw just one of the images binocularly and both of the monocularly presented images, it was determined that one eye was being suppressed and the other eye had the dominant PRL.
Distance visual acuity was--according to the degree of cognitive disability--tested binocularly with Lea numbers, Lea symbols, or Lea gratings.
a A pair of low power compact telescopes is mounted binocularly in carrier lenses with refractive correction
objectively recorded vergence eye movements to a constant-velocity ramp stimulus, in which 28 patients with unspecified categories of TBI binocularly tracked a small target at near that moved continuously in depth from 30 to 5 cm along their midline [40].
Testing binocularly, which is not instructed by the Fletcher test and cannot be done with SLO, to simulate the patients' real-world function and observe their compensatory techniques and better inform the therapist's rehabilitation strategies.
Higher powered adds provided binocularly may require provision of some base in prism to aid convergence, or prescribing the add monocularly to the better eye.
The stimuli were centered in a red square border viewed binocularly that subtended 5.