In bitemporal hemianopsia, which part of vision remains intact?

• A. Central vision remains intact.
• B. Peripheral vision remains intact.
• C. Color vision remains intact.
• D. Night vision remains intact.

Answer: (A)

Bitemporal hemianopsia is caused by a lesion at the optic chiasm that damages the crossing nasal retinal fibers, which carry information from the temporal (outer) visual fields of both eyes. This pattern produces loss of the outer halves of the visual field in each eye. The central vision, mediated by the macula/fovea, tends to be spared because those fibers are closer to the posterior optic pathways and are less affected by typical chiasmal compression. So, the part of vision that remains intact is the central vision.