A nurse is assessing cranial nerve VIII.
What tests will be administered on the client?

Choice A rationale

The abducens cranial nerve (CN VI) controls the lateral rectus muscle of the eye, which is responsible for outward movement. It is not assessed using the Snellen visual acuity chart. The function of this nerve is tested through the evaluation of lateral eye movements.

Choice B rationale

The optic cranial nerve (CN II) is responsible for vision, including visual acuity and visual fields. It is assessed using the Snellen visual acuity chart to determine how well a person can see at various distances. This test evaluates the clarity and sharpness of vision, making CN II the correct answer.

Choice C rationale

The trochlear cranial nerve (CN IV) controls the superior oblique muscle, which helps with downward and inward eye movements. It is not assessed using the Snellen visual acuity chart but rather through the evaluation of eye movements and alignment.

Choice D rationale

The oculomotor cranial nerve (CN III) controls most of the eye's movements, including those of the superior, inferior, and medial rectus muscles, as well as the inferior oblique muscle. It is also responsible for controlling the pupil's response to light. The Snellen visual acuity chart does not assess the function of CN III, as it focuses on visual clarity and acuity.

Choice A rationale

Loss of peripheral vision is more commonly associated with glaucoma, where increased intraocular pressure damages the optic nerve. This condition leads to gradual loss of peripheral vision, often described as "tunnel vision.”. Cataracts typically do not cause this symptom.

Choice B rationale

Cataracts involve the clouding of the eye's natural lens, leading to blurred vision and decreased ability to perceive colors. The clouding scatters light, reducing the clarity of color perception and overall vision. This symptom is consistent with cataract formation.

Choice C rationale

Seeing bright flashes of light and floaters is more commonly associated with retinal detachment or posterior vitreous detachment. These conditions involve changes in the retina or vitreous humor, leading to such visual disturbances. Cataracts do not typically cause these symptoms.

Choice D rationale

Loss of central vision is more commonly associated with age-related macular degeneration (AMD), where the central part of the retina (macula) deteriorates. This condition affects central vision, making activities like reading and recognizing faces difficult. Cataracts primarily cause generalized blurred vision, not central vision loss.