Ophthalmologic apparatus

Abstract

An ophthalmologic apparatus for repeated optical or photometric examination of the fundus or another portion of a patient's eye has an illuminating unit with a light source for a microscope. The optical axis of the microscope can be repeatedly moved to one and the same position relative to a beam of radiation issuing from the center of curvature of the external surface of the cornea in a patient's eye with assistance from a positive field lens which is adjustable with the microscope and acts not unlike an ophthalmoscopic lens for indirect ophthalmoscopy. The lens projects for the microscope a real intermediate image of the selected portion of a patient's eye in an intermediate plane adjacent that focal point of the lens which is remote from the patient's eye. An illuminated or radiation emitting marker is provided at that side of the intermediate plane which faces away from the lens and close to the optical axis of the microscope. The aforementioned components of the apparatus are jointly adjustable by the person in charge along one, two or all three axes which intersect and are inclined relative to each other. Such adjustment is carried out until the intermediate plane receives a sharp image of the selected portion of a patient's eye. A selected portion of the intermediate plane (namely a portion which is observable through the microscope) provides for the microscope a sharp image of the illuminated marker with assistance from a patient's eye in that the external surface of the cornea performs the function of a spherical mirror.

Dependencies are inferred from the claim text.