One ear at a time, cold water is poured into the ear canal and the eyes respond in rapid movements away from the ear with water in it. When warm water is poured into the ear, the eyes move towards that ear.
This simple exam tests the acoustic nerve in your ear and parts of the brain that deal with balance. If the eyes are unresponsive or make random movements, especially when cold water is applied, there could be a problem.
The test is performed on people who have constant dizziness or vertigo and people who have had hearing loss due to certain antibiotics. Although the test is simple, the analysis is tricky and typically done by computerized sensors to measure the eye movement. Once this test shows an abnormality, additional testing is done to confirm the diagnosis.
