Ophthalmological instrument

Claim 1

Ophthalmological instrument for stereoscopic examination and documentation of the fundus of the eye, said instrument comprising means forming an observation beam path and an illumination beam path, said observation beam path having, successively in a direction from the eye (1) of a patient to be examined toward the eye (20) of an observer, a main objective (2) for producing a first inverted flattened image (3') of the fundus (3), a second lens group (4) for focusing such image (3') at infinity, a third lens group (5) for producing a real erect intermediate image (3") at a locus behind said third lens group, a visual field stop (18) at said locus where said erect intermediate image is produced, a fourth lens group (6) for focusing said intermediate image (3") at infinity, a shiftable beam deflection system (10) located beyond said fourth lens group and having at least two positions, one of which intercepts light coming from said fourth lens group and another of which permits passage of at least a portion of the light coming from said fourth lens group, and a stereoscopic observation tube, said stereoscopic observation tube including pupil splitting means (8) located beyond said deflection system to split a pupil beam, an observation light beam from said fourth lens group entering said stereoscopic observation tube when said beam deflection system is in one position and being deflected so as not to enter said tube when said beam deflection system is in another position, said illumination beam path including a perforated mirror having an opening through which said observation beam passes and also including means for projecting an image of a source of light via said perforated mirror into the pupil of the eye of the patient.