Patches called electrodes are placed above, below, and on each side of your eyes. They may be sticky patches or attached to a headband. Another patch is attached to the forehead.
The health care provider will spray cold water or air into each ear canal at separate times. The patches record eye movements that occur when the inner ear and nearby nerves are stimulated by the water or air. When cold water enters the ear, you should have rapid, side-to-side eye movements called nystagmus.
Next, warm water or air is placed into the ear. The eyes should now move rapidly toward the warm water then slowly away.
You may also be asked to use your eyes to track objects, such as flashing lights or moving lines.
The test takes about 90 minutes.