Bupranolol, a beta 1- and beta 2-blocker, causes constriction of the pupil in men

Two out of three normal eyes tested with frequent instillation of 30 microliters of drops of 0.5% bupranolol, a beta 1 + beta 2 blocking drug with some intrinsic sympathomimetic and local anesthetic activity, showed a miotic effect of the order of a 25% reduction of pupil area, as estimated by an open-loop iris-videorecorder. A slight contralateral effect was also observed. Blocking by the drug of tonic inhibitory beta-adrenergic activity on the sphincter muscle of the pupil is postulated.