bitemporal hemianopia

Bitemporal hemianopia is a specific type of visual field defect characterized by the loss of vision in the outer half of the visual field of both eyes. This condition typically arises from a lesion or pressure on the optic chiasm, where the optic nerve fibers from the nasal halves of each retina cross.123

A common cause of pressure on the optic chiasm is a tumor of the pituitary gland. This compression affects the nerve fibers that transmit visual information from the outer parts of the visual field, resulting in the characteristic "blinkers" effect where a person can see straight ahead but not to either side. While other conditions can cause visual field defects, bitemporal hemianopia specifically points to an issue at the optic chiasm.123