This procedure is performed at Munson Audiology's Main Clinic located at Munson Medical Center. Videonystagmography (VNG) is a series of tests that evaluate how well the eyes, inner ear, and brain help a person maintain balance and a sense of position. VNG measures certain involuntary eye movements called nystagmus. These eye movements occur normally when the head is moved. Spontaneous or prolonged nystagmus may be associated with certain conditions that affect the nerves or structures of the inner ear or brain. During VNG testing, the patient wears goggles that track eye movements. The patient is asked to track some lights and change positions. These motions sometimes trigger vertigo or dizziness. Near the end of the test, the audiologist will induce air (warm and cool) into the ear canal. This may or may not cause dizziness. In most cases, the dizziness is very brief.