Overview Introduction When light passes through the lens it reaches the the retina, where the formed image is inverted and reversed login to view 1 more bullet axons leave the retina into the optic nerve fibers pass through the optic chiasm and subsequently in the optic tract login to view 5 more bullets axons in the optic tracts will synapse in the lateral geniculate nucleus (LGN) of the thalamus fibers from the LGN makes it way to the visual cortex as optic radiations login to view 8 more bullets optic radiations eventually synapse in the primary visual cortex superior optic radiations project to the login to view 1 more bullet inferior optic radiations will project to the login to view 1 more bullet Summary of conscious vision perception retina → optic nerve → optic chiasm → optic tract → lateral geniculate body → optic radiation to primary visual cortex Additional pathways retina → optic nerve → optic chiasm → optic tract → pretectal area and superior colliculus the pretectal area is important for the login to view 9 more bullets the superior collicus and pretectal area is important for login to view 1 more bullet Common Lesions Select Visual Field Defects Visual Field Deficit Etiology Central scotoma Macular degeneration Retinal infarction hemorrhage degeneration infection Monocular vision loss Optic neuritis Anterior ischemic optic neuropathy Optic glioma Bitemporal hemianopia Pituitary adenoma Craniopharyngioma Hypothalamic glioma Contralateral homonymous hemianopia Optic tract lesions (rare) secondary to malignancy demyelination infarction Optic radiation lesions Lesion involving the entire primary visual cortex Contralateral superior quadrantanopia ("pie in the sky") Temporal lobe lesions Lesions involving the lower bank of the calcarine fissure Contralateral inferior quadrantanopia ("pie on the floor") Parietal lobe lesions such as infarction of the superior division of the middle cerebral artery Lesions involving the superior bank of the calcarine fissure Homonymous heminanopia with macular sparing Posterior cerebral artery infarction