21. 1 = Central scotoma secondary to optic neuritis 2 = Total blindness of the right eye from a complete lesion of the right optic nerve 3 = Bitemporal hemianopia from a complete lesion of the optic chiasm 4 = Right nasal hemianopia from a perichiasmal lesion 5 = Right homonymous hemianopia from a complete left optic tract lesion 6 = Right homonymous superior quadrantopia caused by partial involvement of the optic radiation in the left temporal lobe (Meyer's loop) 7 = Right homonymous inferior quadrantopia caused by partial involvement of the optic radiation in the left parietal lobe 8 = Right homonymous hemianopia from a complete lesion of the left optic radiation 9 = Right homonymous hemianopia (with macular sparing) from a posterior cerebral artery occlusion causing ischemia of the calcarine cortex of the occipital lobe