Electronystagmography is a battery (group) of eye-movement tests that look for signs of vestibular dysfunction or neurological problems by measuring nystagmus (a kind of involuntary eye movement) and record other eye movements in order to evaluate certain brain functions.

One ENG test evaluates the movement of the eyes as they follow a moving target. Another observes eye movements as the head is positioned in different directions. During the caloric test (sometimes called bi-thermal caloric or mono-thermal caloric), warm or cold air is circulated in the ear canal. The temperature change stimulates the inner ear in order to test the nystagmus response.