Visual loss is a common complaint heard by the neurologist. Because the visual pathways constitute one third of the supratentorial brain mass, they are frequently affected by structural brain lesions and a wide range of neurologic disorders. Accurate localization of visual disturbances is the key to correct diagnosis and appropriate management. Transient monocular visual loss can be the result of vascular diseases as well as ocular disorders. Acute persistent monocular visual loss from an optic nerve disorder usually represents anterior ischemic optic neuropathy, either arteritic or nonarteritic in the elderly patient or idiopathic optic neuritis in the younger patient. Progressive unilateral optic neuropathies are more commonly the result of infiltrative or compressive mechanisms, such as from optic nerve gliomas, optic nerve sheath meningiomas, or sarcoidosis. Transient binocular visual loss usually represents the visual aura of migraine. Persistent binocular visual loss results from damage to both optic nerves, the chiasm, or the retrochiasmal visual pathways. Respect of the vertical meridian on visual field testing indicates a lesion at the chiasm or more posteriorly. Cerebral visual loss can be separated into that which results from damage to the geniculostriate relay and that which results from extrastriate damage. Geniculostriate damage results in focal homonymous hemifield defects that impair all aspects of vision within the affected region. Lesions of extrastriate cortex affect specific types of vision processing, such as color perception, object recognition, face recognition, reading, motion perception, visuospatial analysis, and spatial attention. Additionally, cerebral disorders can generate positive phenomena, such as hallucinations and spatial or temporal perseveration of visual images.