Electronystagmography (ENG)/Videonystagmography (VNG) evaluates a person’s balance, through eye movement (nystagmus). This series of tests can help to determine a site of lesion for balance disorders. During the testing either goggles with an infrared camera or sticker electrodes are used to measure eye movement. The electrodes do not administer any shocks; they simply measure the natural electricity given off by the muscles as they move. One part of the test involves irrigation of cool and warm air; this causes some individuals to feel dizzy. However, it does dissipate quickly. The irrigation causes nystagmus. The nystagmus is measured and an average is determined for each ear to both cool and warm air. These averages are then compared to determine how the person’s inner ear systems are working.