Topical administrations of 1 % solution of both isoxuprine, nylidrin (β-mimetic agents) and of oxprenolol (β-lytic) were found effective in decreasing the intraocular pressure in glaucomatous eyes. No change of the systemic blood pressure occurred. After 8–10 days of treatment with two daily administration, tachyphylaxis begun to be noticed in most cases. Oxprenolol is a nonselective β-receptor-blocking agent, with an intrinsic sympathomimetic activity and a membrane activity. Its administration in 1% solution produced, in glaucomatous eyes, a drop of the ocular pressure with maximum peaks at the 2nd and 3rd hours, and a complete recovery 6–12 h later. A slight myosis was present in 4 of the 6 treated patients. Systemic blood pressure remained unchanged.