Optical system for forming an image of the retina

US4270842A · kind A · utility

Assignee

• Carl Zeiss Stiftung · DE

Inventors

• Franz Muchel · Oberkochen, DE
• Werner Bohning · Oberkochen, DE

Key dates

• Filing date: Apr 12, 1978
• Grant date: Jun 2, 1981
• Expiry date: Apr 12, 1998

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61B3/125
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

An optical system for forming an image of the retina of an eye which is to be examined. The optical system has two groups of lenses which cooperate to form the image. The first lens group is in contact with the cornea of the eye of the patient via the eye liquid or a physiological saline solution. The second lens group is separated from the first group by an air space, and may serve to conjugate the pupil of the patient with the pupil of the doctor or other observer. If desired, the lenses of the first group may have a central opening which receives a light pipe for illuminating the eye of the patient. Also, if desired, the lenses of the second group may include either spherical or aspherical lenses, or a combination of both, or may include one or more Fresnel lenses.