The state of the microciculatory system of the eye cojunctiva was studied in 107 patients suffering from diabetes mellitus and in 30 practically healthy persons. 85% of diabetic patients displayed marked changes in the conjunctival hemodynamics with a deranged tone and structure of microvessels, increase in their permeability and resistance, and also in worstened blood rheological properties. Disturbances of the conjunctival microcirculation observed from the first years of diabetes mellitus onset reached the maximum in the moderately severe form of diabetes over 10 years in duration with intense diabetic microangiopathies. In comparing the results of a study of the conjunctival and retinal vessels, conjunctival microcirculation was found to be disturbed in 68% of patients with the normal ophthalmological picture of the optic fundus and in all patients with diabetic retinopathies. Microphotography of the conjuctival vessels is recommended in patients with diabetes mellitus for early diagnosis of microhemodynamic disturbances.