Electronystagmography (ENG) involves the electrical recording of involuntary eye movements. It is usually performed in the evaluation of dizziness, vertigo, or balance dysfunction. Metal electrodes are placed above, beside, and below each eye to detect eye movements.
Videonystagmography (VNG) provides vestibular examinations and performs electronystagmography without the use of electrodes. Such non-invasive video systems record, analyze, and report eye movements using video imaging technology. VNG requires the individual to wear a pair of infrared goggles and allows recording of actual video images of eye movement in real time.