Central Scotoma Scotoma noticeable blind spot in a normal visual field normal blind spot is on the retina where the optic nerve is due to NO photoreceptors and is not noticeable central scotoma is due to lesion of macula causes loss of central vision Optic Nerve Transection Transection of the optic nerve loss of nasal and temporal visual fields of single eye loss of all visual information from 1 eye Lesion/Compression of Optic Chiasm (Bitemporal Hemianopsia) Patient unable to see in bilateral temporal fields Usually caused by lesion in optic chiasm most commonly associated with pituitary tumors also occurs with craniopharyngiomas, meningiomas, anterior communicating artery aneurysms Lesion of Optic Tract Optic tract contains visual information from: ipsilateral nasal field contralateral temporal field this results in homonymous hemianopsia Lesion of Meyer's Loop Meyer's loop innervates the inferior ipsilateral part of the retina serving the upper contralateral wedge of vision (pie in the sky) Dorsal Optic Radiation Lesion Dorsal optic radiations innervate the ipsilateral superior part of the retina this means that the contralateral inferior wedge of vision is lost Visual Cortex Lesion Unilateral lesion of the visual cortex causes vision loss of the contralateral visual field the central area of vision is often spared because of redundant coverage of this area with the contralateral visual cortex