The pathology of the lacrimal duct unites a whole group of diseases that affect the work of the entire visual apparatus. To assess their patency, the use of radionuclide diagnostic techniques is allowed. However, there are several limitations associated with the small size of the objects under study and with the dose load on the lens of the eye. The latter depends on the activity of the injected radiopharmaceutical, the patency of the lacrimal ducts and the necessary counting statistics to obtain a reliable diagnostic result. The possibility of using the developed portable radiometric system (PRS) in the dynamic scintigraphy mode for dacryoscintigraphic studies of the lacrimal system is studied. To achieve the best ratio "diagnostic result / dose load on the lens", an algorithm for calculating the optimal activity of the injected drug is proposed. For experimental verification of the presented method of dacryoscintigraphy using PRS, a phantom model of the lacrimal system is developed and manufactured. Comparative testing of the PRS and a single-photon emission computed tomography showed that with dacryoscintigraphy, the PRS will have a higher radiation detection efficiency. The increased efficiency of registration either can increas the number of typical dacryoscintigraphic examinations or significantly reduce the time windows in the PRS and, therefore, investigate the finer structure of dynamic curves. исследовать более тонкую структуру динамических кривых.