What does the term homonymous hemianopsia describe?

What does the term homonymous hemianopsia describe?

• A. Loss of color vision in both eyes
• B. Loss of central vision in one eye
• C. Loss of the same visual field in both eyes
• D. Loss of peripheral vision only in one eye

Answer: (C)

Homonymous hemianopsia describes losing the same half of the visual field in both eyes. This pattern appears when a lesion lies after the optic chiasm—in the contralateral post-chiasmal pathways (optic tract, optic radiations, or occipital cortex). Because the nasal retinal fibers cross at the chiasm and the temporal fibers stay on the same side, a right-sided post-chiasmal lesion causes left field loss in both eyes, and a left-sided lesion causes right field loss in both eyes. This is distinct from monocular losses (which involve only one eye) or from color or central vision problems.

Homonymous hemianopsia describes losing the same half of the visual field in both eyes. This pattern appears when a lesion lies after the optic chiasm—in the contralateral post-chiasmal pathways (optic tract, optic radiations, or occipital cortex). Because the nasal retinal fibers cross at the chiasm and the temporal fibers stay on the same side, a right-sided post-chiasmal lesion causes left field loss in both eyes, and a left-sided lesion causes right field loss in both eyes. This is distinct from monocular losses (which involve only one eye) or from color or central vision problems.