Damage to optic chiasm causes which visual defect?

Prepare for the ACVREP Orientation and Mobility (OandM) Exam. Use our study aids and multiple-choice questions, each with detailed explanations. Boost your confidence and succeed!

Multiple Choice

Damage to optic chiasm causes which visual defect?

When the optic chiasm is damaged, the crossing nasal fibers that carry information from the temporal visual field of both eyes are affected. Since these fibers cross here to the opposite side, their loss results in the loss of the outer (temporal) halves of the visual field in both eyes, known as bitemporal hemianopia. This pattern is classically seen with compressive lesions at the chiasm, such as pituitary tumors. If the damage were behind the chiasm, you’d see a homonymous hemianopia in the same side of the field for both eyes, and if a single optic nerve were damaged, you’d have anopia in that eye. Quadrantanopia arises from localized damage to the optic radiations rather than at the chiasm.

When the optic chiasm is damaged, the crossing nasal fibers that carry information from the temporal visual field of both eyes are affected. Since these fibers cross here to the opposite side, their loss results in the loss of the outer (temporal) halves of the visual field in both eyes, known as bitemporal hemianopia. This pattern is classically seen with compressive lesions at the chiasm, such as pituitary tumors. If the damage were behind the chiasm, you’d see a homonymous hemianopia in the same side of the field for both eyes, and if a single optic nerve were damaged, you’d have anopia in that eye. Quadrantanopia arises from localized damage to the optic radiations rather than at the chiasm.

More practice questions