Explain the vestibulo-ocular reflex (VOR) and its role in gaze stabilization during head movements.

• A. It generates compensatory eye movements opposite to head movement to keep images stable on the retina.
• B. It dampens eye movements to reduce visual blur during head motion.
• C. It produces reflexive pupil dilation during head movement.
• D. It relies on proprioceptive neck input rather than vestibular input.

Answer: (B)

The vestibulo-ocular reflex stabilizes your gaze by producing eye movements that counteract head motion. When you move your head, the semicircular canals detect the angular velocity and send signals to the vestibular nuclei. Those signals drive the eye muscles to move the eyes in the opposite direction, at roughly the same speed as the head turn, so the image stays fixed on the retina. This rapid, automatic adjustment lets you keep seeing a stable scene even while you’re in motion.

This is about generating compensatory eye movements, not dampening them. If eye movements were dampened, vision would blur instead of staying stable. Pupil dilation is controlled by autonomic factors and isn’t part of the VOR. Neck proprioception can influence gaze through other reflexes, but the VOR primarily relies on vestibular input from the inner ear. In a healthy system, the VOR gain (eye velocity divided by head velocity) is about 1, allowing close to perfect stabilization across the main axes of head movement, with the ability to adapt to changes over time or with injury.