heminopia
Pronunciation: hem-in-OH-pee-ah
Loss of vision in half of the visual field, typically affecting the same side in both eyes.
Full Definition
Heminopia, more precisely termed hemianopia or hemianopsia, is a visual field defect characterized by loss of vision in approximately half of the visual field in one or both eyes. The condition most commonly presents as homonymous hemianopia, where the same side of the visual field is affected in both eyes due to damage posterior to the optic chiasm. This typically results from lesions in the optic tract, lateral geniculate nucleus, optic radiations, or primary visual cortex. Less commonly, bitemporal hemianopia can occur from lesions at the optic chiasm. Patients may not initially be aware of their visual field loss, particularly if the deficit develops gradually. Heminopia can significantly impact reading, driving, navigation, and social interactions. Assessment requires formal visual field testing, typically using automated perimetry.
Usage
Usage note: Specify whether homonymous, bitemporal, or complete versus incomplete; note impact on functional activities.
In Context
- "The patient's left homonymous heminopia resulted in frequent collisions with objects on her left side during mobility training." — Visual rehabilitation assessment
- "Heminopia was suspected when the patient consistently missed words on the right side of text during reading tasks." — Cognitive assessment findings