[en] The possible applications are discussed of radionuclides in the diagnosis of eye and orbital tumors, in the determination of the cerebrovascular blood flow disturbances and in the scintigraphy of the lacrimal ducts. In view of the small size of the eye, special Geiger-Mueller tubes and semiconductor detectors, especially Li-drifted silicon detectors complete with microcollimators if required, are used for examinations. The choice of a suitable radiopharmaceutical containing a short-lived radionuclide is essential. Phosphorus 32, iodine(131)-diiodofluorescein, technetium(99m)-pertechnate and chloroquine iodinated with ¹³¹I are mainly used for tumor diagnosis. Technetium 99m in the form of pertechnate is mainly used for the study of the cerebrovascular blood flow and the lacrimal duct scintigraphy. Examinations using radionuclides has a number of advantages over contrast radiography. (Ha)