Royal National Institute for the Blind Information and talking book service 
0303 123 9999 
www.rnib.org.uk
Partially Sighted Society 0844 477 4966 www.partsight.org.uk
LOOK (for families of blind/visually impaired children) 0121 428 5038 www.look-uk.org
National Blind Children’s Society 0800 781 14444 www.nbcs.org.uk
| Defect (lesion position) | Description and causes |
|---|---|
Bilateral homonymous hemianopia (1) | Normal eyes; normal pupillary responses; no conscious vision (cortical blindness) Cause: bilateral damage to the visual cortex—usually CVA |
Homonymous hemianopia (1) | Half the visual field is affected symmetrically in both eyes. Macular fibres may be preserved (macular sparing) if the posterior cerebral artery is functional. Cause: strokes involving the middle cerebral artery |
Quadrantanopia (2) | Loss of a homonymous (symmetrical) quadrant of vision indicates temporal lobe disease with superior defect and parietal lobe disease with inferior loss. Causes: vascular events, tumours, trauma |
Bitemporal hemianopia (3) | The temporal side of the visual field is affected in both eyes. If one nerve is completely affected, a junctional scotoma results. Causes: compressive chiasmal lesions, e.g. pituitary tumour, craniopharyngioma, or meningioma |
Altitudinal defect (4) | Field defect respecting the horizontal. Cause: optic nerve disease, e.g. optic neuropathy, optic neuritis |
Enlarged blind spot (4) | Blind spot is enlarged if the optic disc is enlarged. Causes: papilloedema, disc inflammation, infiltration with lymphoma |
Central scotoma (4) | Loss of central vision with normal visual field around it. May be unilateral or bilateral • Bilateral causes toxic (e.g. tobacco), B12 deficiency, MS, age-related macular degeneration, inherited • Unilateral causes glioma of optic nerve, vascular lesion |
Tunnel vision | Loss of peripheral vision in all directions. Causes: glaucoma, retinitis pigmentosa, retinal detachment, functional visual loss (visual fields having no anatomical correspondence) |
Loss of vision from one eye | Due to lesions of the retina or optic nerve anterior to the optic chiasm. Causes: retinal detachment, retinal vein occlusion, optic neuropathy, infiltration of the nerve, demyelination, compression of the nerve |
| Defect (lesion position) | Description and causes |
|---|---|
Bilateral homonymous hemianopia (1) | Normal eyes; normal pupillary responses; no conscious vision (cortical blindness) Cause: bilateral damage to the visual cortex—usually CVA |
Homonymous hemianopia (1) | Half the visual field is affected symmetrically in both eyes. Macular fibres may be preserved (macular sparing) if the posterior cerebral artery is functional. Cause: strokes involving the middle cerebral artery |
Quadrantanopia (2) | Loss of a homonymous (symmetrical) quadrant of vision indicates temporal lobe disease with superior defect and parietal lobe disease with inferior loss. Causes: vascular events, tumours, trauma |
Bitemporal hemianopia (3) | The temporal side of the visual field is affected in both eyes. If one nerve is completely affected, a junctional scotoma results. Causes: compressive chiasmal lesions, e.g. pituitary tumour, craniopharyngioma, or meningioma |
Altitudinal defect (4) | Field defect respecting the horizontal. Cause: optic nerve disease, e.g. optic neuropathy, optic neuritis |
Enlarged blind spot (4) | Blind spot is enlarged if the optic disc is enlarged. Causes: papilloedema, disc inflammation, infiltration with lymphoma |
Central scotoma (4) | Loss of central vision with normal visual field around it. May be unilateral or bilateral • Bilateral causes toxic (e.g. tobacco), B12 deficiency, MS, age-related macular degeneration, inherited • Unilateral causes glioma of optic nerve, vascular lesion |
Tunnel vision | Loss of peripheral vision in all directions. Causes: glaucoma, retinitis pigmentosa, retinal detachment, functional visual loss (visual fields having no anatomical correspondence) |
Loss of vision from one eye | Due to lesions of the retina or optic nerve anterior to the optic chiasm. Causes: retinal detachment, retinal vein occlusion, optic neuropathy, infiltration of the nerve, demyelination, compression of the nerve |
