Although cerebral blindness is well known and has been described in numerous communications,37,28,8 detailed studies, particularly those relating to changes in the visual functions over the course of time, have been limited. Thus the condition of the fields of vision before blindness is rarely known, and the history of the onset is often incomplete. Moreover patients usually have severe mental disturbances which make it impossible to determine whether they are totally blind. When there is residual vision, perimetry and other visual studies are difficult. Finally, in most instances there is little information on the degree and mode of recovery from the "blindness."
In practice, the most frequent cause of cerebral blindness is occlusive vascular disease involving both occipital lobes.37 Cerebral blindness which is often incomplete may also occur in other conditions, among them being complications of ventriculography28 and carotid angiography.38,13 Cases have been reported following catheter