Eye refractmeters using infrared rays

Claim 1

Eye refractmeter comprising a target projecting optical system including objective lens means for projecting an image of target means through the pupil of a patient's eye to produce a target image on retina of the eye, an observing optical system for observing the target image through the pupil and the objective lens means, and a sighting optical system for observing light reflected at an anterior segment of the eye to determine that the objective lens means is appropriately apart from the patient's eye, means being provided in said projecting optical system so that the image of the target means is projected by an infrared ray, said target projecting optical system including means for directing at least two target projecting light bundles through said pupil in different angles, said target projecting optical system further including aperture means located substantially in conjugate with the pupil with respect to the objective lens means, said aperture means including within a circle corresponding to the pupil a pair of substantially semicircular apertures located with their chord portions opposed to each other with a space therebetween, said observing optical system including second aperture means located substantially in conjugate with the pupil with respect to the objective lens means, said second aperture means including a slot located in a position corresponding to the space between said semicircular apertures.