A device consisting of a rotating disk with lenses that is placed in front of a patient's eyes to examine their refractive state.
An instrument used by the eye doctor to determine the degree of myopia (nearsightedness), hyperopia (farsightedness) or astigmatism that is present in the patient's eye.
Device containing lenses of varying strengths that help an eye doctor to determine a patient's prescription, whether he is near- or far-sighted, and if she has astigmatism. The patient sits in a chair and looks into the phoropter, and views an eye chart about 20 feet away. The doctor moves different lenses in front of each eye and asks the patient whether the vision is better or worse.
a machine used to detect refractive errors
an instrument commonly used by an optometrist or other eye care professional during an eye examination to determine an individual's eyeglass prescription
an optical instrument using a selectable series of intricate lenses that the patient looks through until maximum clarity is obtained, thus arriving at the patient's precise prescription.
An optical instrument containing many lenses which is used to determine the power of glasses or refractive error.
Device that provides various combinations of lenses used for tests of vision errors in eye examinations.
An instrument of determining the refractive state of the eye.
A phoropter (or phoroptor) is an instrument commonly used by optometrists and ophthalmologists during an eye examination to measure an individual's refractive error and determine his or her eyeglass prescription. Typically, the patient sits behind the phoropter, and looks through it at an eye chart placed at optical infinity (20 feet or 6 meters), then at near (16 inches or 40 centimeters) for individuals needing reading glasses. The optometrist then changes lenses and other settings, while asking the patient for subjective feedback on which settings gave the best vision.
