Binasal hemianopsia

Binasal hemianopsia is the medical description of a type of partial blindness that is associated with certain lesions of the eye, and of the central nervous system, such as congenital hydrocephlus.

The absence of vision in half of a visual field is described as hemianopsia.

The visual field of each eye can be divided in two vertically, with the outer half being described as temporal, and the inner half being described as nasal.

In binasal hemianopsia vision is missing in the inner half of both the right and left visual fields.

Binasal hemianopsia can be broken down as follows:
 * bi-: involves both left and right visual fields
 * nasal: involves the nasal visual field
 * hemi-: involves half of each visual field
 * anopsia: blindness