In 2 models of reduced cerebral blood flow-permanent occlusion of the vertebral arteries plus transient occlusion of the common carotid arteries (4VO) and transient clamping of the common carotid arteries (BCCA)-the acute effects on the electrical function of the retina were monitored by recording the photopic electroretinogram. During both 4VO and BCCA the amplitude of the b-wave was reduced. Within 30 min of reperfusion after 4VO and after BCCA the b-wave had fully recovered. In contrast, the a-wave was not affected by either treatment. The data suggest that occlusion of common carotid arteries leads to retinal ischemia and might represent a useful model of amaurosis fugax.