What symptom is associated with damage to cranial nerve II (optic nerve)?

Damage to cranial nerve II, the optic nerve, primarily affects vision as this nerve is responsible for transmitting visual information from the retina to the brain. Monocular blindness occurs when there is a disruption in the functionality of this nerve, leading to a loss of vision in one eye. This symptom can arise from various causes such as trauma, diseases affecting the optic nerve, or conditions like glaucoma.

In contrast, pupil constriction is primarily controlled by cranial nerve III (oculomotor nerve), which regulates the muscles that constrict the pupil. Hearing loss is associated with cranial nerve VIII (vestibulocochlear nerve), which is responsible for auditory function. Loss of facial symmetry typically involves cranial nerve VII (facial nerve), which controls the muscles of facial expression. Therefore, monocular blindness is the correct symptom linked to the damage of cranial nerve II.