A very through ocular examination was made in 48 hypertensive patients treated for 18 months with acebutolol in a daily dose of between 400 and 2400 mg. Abnormal symptoms in the form of a prickling sensation were seen in two cases. Microscopic punctate lesions of the conjunctive were seen in 9 subjects, either with the Bengal Pink or fluorescein tests. These very slight microscopic lesions were found in general only in the region of the palpebral slits, a zone normaly exposed to microtrauma, which decreases the value of this finding. The results of a Schirmer test were considered to be abnormal in six patients. These ocular abnormalities were generally mild and it could not be shown conclusively that they were related to treatment with acebutolol. Ocular surveillance, with examinations repeated every six months, indicated the absence of any harmful effect on the eye of prolonged used of acebutolol in the treatment of hypertension.