True saccular aneurysms of the ophthalmic artery are extremely rare; they may produce severe conduction disorders of the optic nerve by compression or hemorrhage. Carotid-ophthalmic artery aneurysms, which originate on the medial or superomedial surface of the internal carotid artery at or near the origin of the ophthalmic artery, are much more frequent. This paper describes signs and symptoms as well as modern microsurgical treatment, and reports the results obtained in a group of 33 patients with a total of 40 carotid-ophthalmic artery aneurysms.