Nineteen patients who complained of red eyes had the characteristic clinical signs of an atypical carotid-cavernous fistula. Episcleral veins were dilated, intraocular pressure and episcleral venous pressure were high, and blood filled Schlemm's canal during gonioscopy. Most of the patients had mild exophthalmos, but in none was the exophthalmos obviously pulsatile, and in only two patients could a bruit be heard. Orbital echography disclosed either a dilated superior ophthalmic vein or congestion of the orbital soft tissues. Selective carotid angiography, done in seven patients, disclosed the fistula to be a dural-cavernous fistula. The serious complication of the fistulas was open-angle glaucoma resulting from the high episcleral venous pressure. None of the fistulas was treated surgically, but six closed spontaneously and three closed soon after carotid angiography.