Vestibulo-Ocular Reflex (VOR)

The vestibulo-ocular reflex, also known as VOR or oculovestibular reflex, is a reflex of the eye that helps you maintain clear vision and balance. A reflex is an automatic action that you can’t control. It manages your eye and head movements. When your head moves in one direction, your vestibulo-ocular reflex makes your eyes move in the opposite direction. This constant balancing act helps you:

• See clearly: It prevents blurred vision. Clear vision happens because your retina senses light and sends images to your brain. Those images may blur if they don’t stay at one point in your retina when you move your head.
• Maintain your gaze: When your head or body moves in one direction, the vestibulo-ocular reflex makes your eye muscles move your eyes the other way. In other words, it literally helps you to keep your eye on the ball.
• Manage coordination: The VOR partners with your vestibular spinal reflex (VSR) to help you maintain your balance. When you move your head, your VSR triggers muscles in your arms, legs, neck and torso while your VOR sends signals to your eye muscles.

How does the oculovestibular reflex work?

The connection between your ears and eyes makes your VOR work. The process starts with the tiny organs deep within your inner ear:

1. The organs notify your vestibulocochlear nerve in your peripheral nervous system that your head is in motion.
2. The nerve signals your brainstem in your central nervous system. Your brainstem manages your vestibular-ocular reflex, among many other reflexes. It activates your VOR.
3. Your VOR turns on your eye muscles.
4. Your eye muscles make your eyes move at the same speed as your head movement, but in the opposite direction.

For example, say you’re walking to a bus waiting at the curb. You’re moving fast, turning left and right so you don’t run into anyone. But your eyes stay focused on the bus, so you know if you need to sprint to keep it from leaving without you.

That’s your vestibulo-ocular reflex in action. It constantly keeps your eyes moving in the opposite direction of your head, no matter how fast you move it.

What conditions affect my vestibulo-ocular reflex?

Several vestibular disorders that affect your inner ear or vestibular nerve can have an impact on your oculovestibular reflex. Other conditions may affect the part of your central nervous system that triggers your VOR. Examples of these conditions include:

• Benign paroxysmal positional vertigo (BPPV) can block communication between nerve, brainstem and eye muscles.
• Brain tumors can affect your brainstem, so it doesn’t trigger your VOR.
• Vestibular neuritis may damage the nerve that sends signals to your brainstem.
• Traumatic brain injuries may disrupt the process that activates your vestibulo-ocular reflex.

Symptoms of issues with your vestibulo-ocular reflex may include:

• Blurred vision
• Dizziness
• Nausea
• Spinning sensation

Tests to check your vestibulo-ocular reflex

Healthcare providers may do tests to diagnose conditions that affect the oculovestibular reflex, including:

• Head impulse test: In this test, you keep your eyes on an object while a provider quickly moves your head to one side. They do this to see if your eyes stay focused on the object instead of moving in the same direction as your head.
• Doll’s eye reflex (oculocephalic reflex) test: This is another test to see if your eye movements follow your head movement. Providers may do this test to check your brainstem.
• Rotary chair test: This test is a kind of vestibular testing. You sit in a motorized chair wearing goggles with cameras. The cameras track your eye movement as the chair moves right and left.
• Caloric test: Providers use this test to check the organs in your inner ear that manage your balance. These organs start the process that triggers VOR. The caloric test involves placing warm or cold water in your ear to see if the sensation makes your eyes move uncontrollably.