The corneal neurotrophic status was evaluated in 110 patients (220 eyes) with diabetes mellitus and in 20 normal controls (40 eyes). Corneal abnormalities (gerontoxon, limb vascularization, punctate keratopathy, endothelial dystrophy, relapsing erosion, corneal ulcers) were detected in 73.6% diabetics. Corneal changes depended on the type, duration, and compensation of diabetes mellitus. Based on the diagnostic markers (threshold sensitivity of the cornea, microcirculatory status, bulbar conjunctiva status, level of lacrimal production, cellular composition of the limb smears impressions, lacrimal levels of catecholamines, hydroperoxides, and lipids), three types of diabetic neuropathy of the cornea were distinguished: vegetative, sensory, and vegetosensory. Corneal changes were associated with signs of diabetic neuropathy in 55.6% cases and with autonomic nervous disorders of the cardiovascular system in 46.9% cases, which evidences a generalized involvement. The detected neurotrophic features of the cornea should be borne in mind when choosing pathogenetic therapy for diabetics with corneal complications and preparing the patients to ocular surgery.