Apparatus and method to measure visual function under simulated nighttime conditions
OwnerStephen L. Trokelinventor
Life of this patent
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Abstract
An apparatus and method for measuring visual function under simulated nighttime conditions where the pupil is large by maintaining extremely low ambient illumination when the test is performed in a darkened room, the apparatus including a test field defining a plurality of recognizable indicia of variable irradiance which appear on a black background having zero irradiance, the test field being either transilluminated or illuminated by projection, and a field stop having a plurality of apertures of progressive sizes which are placed in front of the eye of the person being tested to ascertain the true functional optical zone of the cornea.
Claims9
An apparatus for testing visual function of a person following refractive surgical procedures where the corneal optics have been modified, under simulated nighttime conditions when the pupil is large, comprising:
- a test field having recognizable indicia of variable irradiance which appear on a light absorbing, completely black background having substantially zero irradiance to maximize pupillary size during the test;
- whereby said indicia of variable irradiance provide a bright resolution target for the person being tested while said black background of substantially zero-irradiance maintains extremely low ambient illumination when the test is performed in a darkened room.
A method for testing visual function of a person following refractive surgical procedures where the corneal optics have been modified, under simulated nighttime conditions when the pupil is large, comprising the steps of:
- (a) providing a test field of recognizable indicia of variable irradiance which appear on a light absorbing, completely black background having substantially zero irradiance in a darkened room to maximize pupillary size during the test;
- (b) positioning a person to be tested in said darkened room relative to said test field;
- (c) varying the irradiance of said indicia;
- (d) having said person identify said indicia;
- and
- (e) measuring the quality of vision under varying test conditions.
Dependencies are inferred from the claim text.