Videonystagmoscopy (VNS) testing is used to determine if a vestibular (inner ear) disease may be causing a balance or dizziness problem, and is one of the only tests available today that can decipher between a unilateral (one ear) and bilateral (both ears) vestibular loss. VNS testing is a series of tests designed to document how well the eyes respond to information from the vestibular system.

This test also addresses the functionality of each ear and if a vestibular deficit may be the cause of a dizziness or balance problem. To monitor the movements of the eyes, infrared goggles are placed around the eyes to record eye movements during testing. VNS testing is non-invasive, and only minor discomfort is felt by the patients during testing as a result of wearing goggles.