WERNICKE'S disease is a clinical and pathological entity in which ocular motor signs are the most constant finding. Yet extraordinarily few descriptions of it have been reported in the ophthalmic literature,* and little attempt has been made to analyze the diversity of its ocular manifestations. This is remarkable when one considers that without the eye signs one cannot make a clinical diagnosis of Wernicke's disease. Moreover, a quick and accurate recognition of the condition is not merely of academic interest; it becomes a matter of prime practical importance, since this disease has a serious prognosis unless treated specifically and promptly. It is our purpose to draw attention to the ocular manifestations of Wernicke's disease, on the basis of the study of five cases, and to point out the manner in which they may be utilized in the diagnosis of the condition. In 1881, Carl Wernicke3 described a fatal illness