I can remember many days of my childhood spent hanging onto the handles of the neighborhood merry-go-round as it was spun into dizzying speeds by an adult. I was always fascinated by the resulting sensation that the world was spinning around me once I got off the whirling apparatus. What I know now is that the sensation of the world spinning around me was Physiological Nystagmus, which is involuntary eye movement that is part of the vestibulo-ocular reflex (VOR). This is what creates the visual sensation of movement when we are dizzy.
Our visual system is a complex interaction of many different systems in the brain and body and encompasses more than just the ability to see clearly. It describes our ability to understand what we see and to use that understanding to move and thrive in our many environments. Part of the visual system’s input comes from our vestibular system.
According to Josephine Moore, the vestibular system is like a tripod stand that holds a camera, in that it helps hold the head stable so that the eyes can focus on an object. It contributes to bilateral integration which is important for simultaneous functioning of the two eyes together and smooth eye movements across the visual midline.There are receptors located within the inner ear, which respond to gravity and detect motion and change of head position. They tell us where we are in relationship to gravity, if we are moving or at rest, and our speed and direction of movement. The vestibular system is a powerful integrator that interacts with all other sensory systems. It most noticeably impacts our posture, balance, muscle tone, and bilateral coordination.
Imagine the complex brain activity and coordination needed in order for a child to visually follow, move forward, and catch a ball. The child will need to fixate on and track the moving ball with their eyes. Proprioceptors (specialized motion detectors) in the neck, eyes, and body help to coordinate the child’s movements of their legs and hands. The proprioceptors and the vestibular system will orient the head and eyesto effectively track the ball as the child moves forward and reaches for the ball. Timing and spatial awareness will allow the child to grasp the ball midair. All of these inputs together – especially the coordination between the visual and vestibular systems – are important in providing a foundation for the timing and spatial orientation of the child’s movements. When properly integrated our vision and vestibular systemsallow for us to move within our environments effectively, securely and comfortably.
In school, it is estimated that at least 75% of classroom learning occurs through visual pathways. If a child is experiencing any visual difficulties, such as poor vision-vestibular integration, learning will most likely be impacted. Children with visual-vestibular issues may:
- Crave constant physical support from adults, such as being held, rocked, guided, etc.
- Have difficulty with going up or down stairs
- Get car sick frequently or generally dislike rides in the car
- Avoid swings or playground equipment (swings, merry-go-rounds, ands slides)
- Experience delays with reading and writing
- Have difficulty with gross motor skills such as riding a bike, ball skills, running, or jumping
- Stumble or fall frequently
- Appear to not get dizzy even after spinning for a long time
- Seem to enjoy fast movement like swinging
Virginia Vision Therapy Center offers specialized intervention to support visual-vestibular coordination for those in need. The visual and vestibular systems provide the foundation for skillful and comfortable movement through the many environments we live, learn and work in, as well as for efficient intake of visual information for learning.