Method and apparatus for eye refraction determination
AssigneeHerbert Schwind GmbH & Co. KG
InventorJosef Reiner
Life of this patent
Estimating the term…
Abstract
Method and apparatus for determining eye refraction using corrective lenses comprising projecting the corrective lens by means of an optical system into the pupil of the eye or in a predetermined spaced relation in front of said pupil, e.g., via a splitting mirror; this permits sight testing without the use of test spectacles and impairment of field of vision.
Claims8
A method for determining eye refraction using corrective lenses which method comprises spacing the corrective lens at a distance from the eye to be examined and projecting an image of the corrective lens into the pupil of the eye or at a predetermined spaced relation in front of said pupil by positioning at least one optical element including a beam splitter mirror in the light path between the corrective lens and the eye to be examined with the corrective lens positioned out of the line of vision of the eye to be examined to simulate the positioning of the corrective lens at the selected one of into or in front of the pupil and to simulate vision in free space by the eye to be examined of an optotype imaged on the corrective lens.
In an apparatus for determining eye refraction of the type wherein different corrective lenses are sequentially used for the determination, the improvement comprising means for mounting the corrective lenses at a distance spaced from the eye to be examined out of the line of sight of the eye to be examined and means for projecting an image of the corrective lens into the pupil of the eye or at a predetermined spaced relation in front of the pupil including at least one optical element comprising a beam splitter mirror in the light path between the corrective lens and the eye.
Dependencies are inferred from the claim text.