Electronystagmography (ENG) is a diagnostic test used to assess the function of the vestibular system, which helps control balance and eye movements. During the test, small electrodes are placed around the eyes to measure electrical activity as the patient follows visual stimuli or experiences changes in head position. The data collected during ENG helps identify issues related to vertigo, dizziness, or balance disorders. By analyzing eye movements, healthcare professionals can determine if the problem originates from the inner ear or the central nervous system, guiding appropriate treatment options.