Electronystagmography, often abbreviated as ENG, is a diagnostic test used to evaluate the vestibular system in the inner ear. However, there are several synonyms for this medical procedure. These include videonystagmography (VNG), which uses a camera to record eye movements instead of electrodes, and oculography, a method of measuring eye movements without any external stimulation. Other synonyms for electronystagmography include electronysmography, electro-oculography, and the newer term, videonystagmography-rotary chair testing (VNG-RCT). Regardless of the name, all of these tests are designed to detect and diagnose issues with the vestibular system, which is responsible for balance and spatial orientation.