[Coaxial illumination in the Zeiss Jena 310 and 311 microscopes]

Safe implementation of planned cataract extraction calls for perfect instruments but also for a high standard surgical microscope with coaxial illumination to produce a red reflex on the pupil. Microscopes of Zeiss Jena 310 and 311, which are used in the majority of ophthalmological departments, lack this type of illumination and this impedes wider application of extracapsular cataract extractions. The author gives an account on the possibility of installing coaxial illumination ex post. He mentions briefly a design presented in Dĕcín and suggests his own modification which he tested. As optic conductors are not available and are the basis of the equipment, the author elaborated a solution of his own and uses the proposed equipment during operations. It does not require optic cables with optic terminals, nor a new source of light.