Visual Field Deficit

Synonyms

Scotoma; Visual field loss

Short Description or Definition

A visual field deficit refers to diminished or absent vision in circumscribed parts of the visual field.

Categorization

Visual field deficits are caused by lesions at different levels of the visual system. Lesions at the retinal level result in scotoma of the affected eye. Optic nerve lesions peripheral to the partial crossing of fibers at the optic chiasm usually cause visual field deficits for one eye only (i.e., unilateral or monocular, incongruent defect). Lesions of the chiasm, optic tract, lateral geniculate nucleus, optic radiations, and primary visual cortex produce deficits in the contralateral visual hemifield that are roughly congruent for both eyes (i.e., covering the same area when tested monocularly (Fahle 2003)).

There are four general types of visual field defects. Altitudinal defectsoccur with partial damage to an optic nerve and consist of a deficit in part or all of the nasal and temporal fields...