What is the role of the optic nerve?

• A. Carries visual data to the brain.
• B. Controls pupil size.
• C. Produces aqueous humor.
• D. Detects light directly.

Answer: (A)

The optic nerve’s role is to carry visual data from the retina to the brain. After light is detected by photoreceptors in the retina, the captured information is processed by retinal neurons and the resulting electrical signals travel along retinal ganglion cell axons that form the optic nerve. These signals are then relayed toward the brain, reaching the visual cortex for processing and perception. The optic nerve itself does not regulate pupil size, does not produce aqueous humor, and does not detect light directly—those functions belong to other structures: pupil size is controlled by the iris via the oculomotor pathway, aqueous humor is produced by the ciliary body, and photoreceptors in the retina detect light.