Optics: eye examining – vision testing and correcting – Eye examining or testing instrument – Objective type
Patent
1986-08-15
1989-05-30
Arnold, Bruce Y.
Optics: eye examining, vision testing and correcting
Eye examining or testing instrument
Objective type
351206, A61B 310, A61B 314
Patent
active
048345288
ABSTRACT:
A retinoscope utilizing a plurality of infrared light sources each positioned at a difference distance, or eccentricity, from the optical axis of a camera is disclosed. The plural light sources are scanned while the fundus reflex is observed. Whether or not a reflex can be detected depends on the defocus of the eye relative to the camera, the pupil size, the eccentricity of the light source from the optical axis, and the camera-to-subject distance. The light sources are preferably light emitting diodes which are flashed repeatedly and sequentially. One-half of the camera aperture is occluded to permit determination of the amount and the direction of defocus. By noting which LED just creates a crescent of light in the pupil, and by measuring the pupil diameter, the relative defocus of the eye is determined.
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Farkas Leslie
Howland Howard C.
Schaeffel Frank
Arnold Bruce Y.
Cornell Research Foundation Inc.
Ryan Jay
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