phoropter


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phoropter

 [for-op´ter]
an instrument for evaluation of vision, with lenses placed on dials in a unit that is positioned in front of the patient. See illustration.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

Phoropter

The instrument used to measure refractive status of the eyes. It contains many lenses which are then changed in front of the eyes while the patient is looking at an eye chart. This is when the doctor usually asks, "Which is better, one or two?"
Mentioned in: Visual Impairment
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.

phoropter 

An instrument for measuring the ametropias, phorias and the amplitude of accommodation of the eyes. It consists of a large unit placed in front of the patient's head in which there are three rotating discs containing convex and concave spherical and cylindrical lenses, as well as occluders, Maddox rods, pinholes, Polaroids, prisms and coloured filters. An attachment on the instrument allows sets of rotary prisms and cross-cylinders to be swung in front of each sight hole (Fig. P9). Syn. refracting unit; refractor; refractor head. See Simultantest; trial case.
Fig. P9 Phoropter (Topcon)enlarge picture
Fig. P9 Phoropter (Topcon)
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann
References in periodicals archive ?
Wang, "Stereoacuity measurement using a phoropter combined with two 4K smartphones," Clinical and Experimental Optometry, vol.
Horizontal and vertical near von Graefe heterophoria (phoropter).
It perhaps goes without saying that phoropter heads are not used and instead trial lenses and a trial frame, along with other accompanying refraction aids are the mainstay of domiciliary sight tests.
Near visual acuity was measured using a card on a phoropter rod with the patient's distance refraction placed in the phoropter.
The patient is asked to read letters from a chart ripped down the middle while looking through a phoropter that is missing half the lenses.
Every trial case or phoropter contains a set of prisms, therefore, it is easy for any optometrist to access the tools required for a PCT.
Establishing the lead or lag of accommodation can prove helpful and is a test that can be done straight after refraction while the trial frame or phoropter is still in place.
These sensors, combined with the phoropter head, are said to enable Eye Refract to automatically correct visual defects.
During the show, the company will showcase some of its key products, including the Nidek Tonoref III, the Nidek RT-5100 auto phoropter and the Nidek Retina Scan Duo OCT.
Ms Battersby said that using an electronic phoropter head put less strain on practitioners' bodies, as less twisting and bending was required to operate it.