Patent ID: 7810929

Claim:
An optical system for observing or photographing a fundus of an eye with a substantially coaxial illumination beam path and imaging beam path, the optical system comprising: a lens system of at least four lenses; wherein at least two lenses of the at least four lenses are tilted with respect to their optical axes relative to the illumination beam path and imaging beam path; wherein the optical axes of the two lenses and optical axis of the illumination beam path and imaging beam path lie in a first plane; wherein at least two other lenses of the at least four lenses are tilted with respect to their optical axes relative to the illumination beam path and imaging beam path; wherein the optical axes of the two other lenses and optical axis of the illumination beam path and imaging beam path lie in a second plane which intersects the first plane substantially along the optical axis of the illumination beam path and imaging beam path; and wherein the optical axis of the illumination beam path and imaging beam path penetrates the lens outside their optical axes.