Fig. 1 The visual-sensory system. The left cerebral hemisphere has been removed, with the exception of the occipital lobe and the ventricular system. The left lateral geniculate body is hidden (arrow). Note the following relationships: optic nerve with internal carotid and anterior communicating arteries, chiasm in the floor of third ventricle, forward sweep of temporal radiations around lateral ventricle, course of occipital radiations toward interhemispheral surface of occipital lobe. The cerebral falx and cerebellar tentorium are not illustrated.