A test called a videonystagmography, or VNG test may be ordered if you are experiencing significant balance difficulties. The VNG measures the balance center of the inner ear referred to as the vestibular system and allows us to determine if this area is the cause of the dizziness. During this test you will be asked to perform some head movements and follow moving objects with your eyes. Warm or cold air will also be placed in your ears. Eye movements will be recorded and analyzed for involuntary rapid eye movements called nystagmus.