Healthy
The vHIT is a measure of the patient’s vestibulo-ocular reflex (VOR) in response to head movement. A patient with a healthy vestibular system should be able to keep his eyes focused on a stationary target, even if the head is in motion.
Dysfunction
In patients with vestibular dysfunction, when the head moves, the eyes will move with the head, requiring a corrective movement back to the target (this is known as a “catch-up saccade”).