Binasal hemianopsia is the medical description of a type of partial blindness where vision is missing in the inner half of both the right and left visual field.

In binasal hemianopsia, vision is missing in the inner (nasal or medial) half of both the right and left visual fields.

Information from the nasal visual field falls on the temporal (lateral) retina.

Calcification of the internal carotid arteries can impinge the uncrossed, lateral retinal fibers, leading to loss of vision in the nasal field.

Clinical testing of visual fields (by confrontation) can produce a false positive result, particularly in inferior nasal quadrants.