Antioxidant activity (AOA) of lacrimal fluid and blood plasma was studied in 10 normal subjects (20 eyes) and 35 patients with primary open-angle glaucoma (POAG) (67 eyes with glaucoma at different stages). The findings indicate that the progress of glaucoma is paralleled by a gradual decrease in the lacrimal fluid AOA, which becomes significant at the third stage of POAG. Plasma AOA also decreased significantly in the third far advanced stage. A course of total antioxidant therapy including oral aevit and vitamin complexes and intramuscular ascorbic acid normalized plasma AOA even in patients with far advanced glaucoma, while the lacrimal AOA did not normalize. Therefore, local antioxidants are preferable in glaucoma patients.