In homonymous hemianopia - literally, a loss of vision on the same side in both eyes - the field loss is usually the result of a lesion in the optic radiation or tract on one side. The visual defect is dependent on the site of the lesion:
- right-hand sided lesions lead to left temporal and right nasal field loss
- left-hand sided lesions lead to right temporal and left nasal field loss
Macular vision is usually lost in lesions arising in the optic tract; it is usually spared in lesions arising in the more posterior optic radiation.
Causes of homonymous hemianopia include vascular disease, head injury or cerebral tumours.
Last reviewed 01/2018