Oculomotor Movements as the Foundation of Visually Processing Our World

By Kara Christy, MS, OTRL, CBIS

“Vision plays a dominant role in motor development and the motivation to move”.
 – Linda Gerra, American Occupational Therapy Association Annual Conference 2016

Eighty percent of all learning occurs visually. Visual dysfunction occurs in 50-70% of all acquired brain injuries, making learning new strategies and re-learning skills challenging if not addressed. Our visual system is a hierarchy, with oculomotor control – or eye movement abilities – paired with appropriate acuity forming the foundational base of that hierarchy. This includes visual pursuits, visual saccades, scanning, and vergences. To visually attend to and process the world around us, this foundation must be strong, accurate, and efficient. When impacted, our ability to attend, process, recall, move through, and make decisions about our visual surroundings becomes challenging.

What are oculomotor skills and why are they important?

• Visual scanning: Coordinating eye movement in an organized fashion (efficient search pattern) while actively searching the environment for information.
  • Functional use: Looking for items in a grocery store, scanning for hazards at a 4-way stop while driving, searching for a favorite toy on a shelf, locating an entry in a checkbook register.
• Visual Saccades: Eye saccades are quick, simultaneous movements of both eyes in the same direction, usually toward a target.
  • Functional use: Reading, moving your eyes to different faces in a crowd, comparing two products at a grocery store, following notes on sheet music.
• Visual Pursuit: Following a moving target with the eyes.
  • Functional use: Watching a ball during a sports game, tracking traffic while merging onto the freeway, watching a child run at the playground.
• Convergence: The simultaneous inward movement of both eyes toward each other, usually in an effort to maintain single vision with both eyes when viewing an object up close.
  • Functional use: Reading, medication management, threading a needle, using a phone or tablet, completing a puzzle or game.
• Divergence: The synchronized outward movement of both eyes away from each other, usually in an effort to maintain single binocular vision when viewing an object far away.
  • Functional use: Driving, watching an event from a stadium or auditorium, hiking, playing on a playground.
• Vergence Facility: The ability to alternate ocular posture between convergence (near) and divergence (far) while maintaining single binocular vision.
  • Functional use: Looking between a car dashboard and the road environment, reading a grocery list and scanning a grocery aisle, taking notes from a screen or board in a classroom.
• Visual Spatial Deficits:
  • Focal Vision: Aiming your eye directly at an object causes focalization by the brain through the macula. This is the “what” we look at.
  • Ambient Vision: Lets you know where you are in space and provides general information used for balance, movement, coordination, and posture. This is the “where” we are looking.
  • Post Trauma Vision Syndrome: A disruption of the visual process. This disruption affects the neurological system innervating the extraocular muscles that control eye movements, as well as the system regulating focus. This often causes high anxiety with the perception of stationary objects moving or tilting. Common characteristics with this include convergence insufficiency and oculomotor dysfunction.
  • Visual Midline Shift Syndrome: The ambient visual process changes its orientation and concept of the bodily midline; our perception of being centered is off.
    • Functional use: Participating in sports, walking in a straight line (functional mobility), driving a vehicle, navigating curbs, grocery shopping.

Common Symptoms

Deficits with oculomotor control commonly follow an acquired brain injury. Knowing what symptoms to monitor is key to finding help. If an individual experiences persistent symptoms from the list below, seek an evaluation with the appropriate healthcare provider.

Who can help?

• Neurovisual / Behavioral Optometrists (NVO): a health care provider specializing in vision therapy and prism lenses, an expanded area of optometry. They may help improve the flow and processing between the eyes and the brain. NVOs follow a holistic and functional approach to vision care looking at behaviors and abilities, and relating them to visual skills. NVOs view vision as a learned sense that may be improved and/or enhanced. This type of optometrist examines the visual system beyond the health of the eye itself. Evaluations are extended to include tests beyond acuity, depth perception, and visual fields. An NVO will determine how the eyes work together, focus together on a single object, process information, and move. To locate a provider, visit COVD.org
• Occupational and Physical Therapists: It is within the scope of OTs and PTs to address oculomotor movement dysfunctions post acquired brain injury. Neuro specialized therapists can address foundational skills through remediation following training, as well as create a plan of care to work toward bigger functional goals impacted by oculomotor dysfunction. Collaboration with an NVO is key to monitor progress of the foundational deficits, as well as prescribe and adjust prism lenses when applicable.
• Client/Caregiver: Prior to an appointment with a NVO, OT, and/or PT, things can be done to help set the client and their environment up for success.
  • Limit screen time: Extended time on phone, tablet, and computer screens can increase symptoms. When work or school requires the use of a screen, build in regular breaks to allow for visual rest. (Note: Rest breaks are not scrolling through a phone)
  • Follow the 20/20/20 rule: Every 20 minute, look 20 feet away, for approximately 20 seconds to allow for visual rest
  • Use a blue light filter on phones, tablets, or computers
  • Wear blue light filtered glasses when on a screen
  • Dim lights in the environment
  • Print materials needed off from a screen when possible
  • Listen to audio versions of books/textbooks
  • Increase text/font size whenever possible
  • When possible, avoid visually busy environments
  • Take rest breaks. Rest breaks can be short and should have little to no visual input
  • Advocate:
    • To see appropriate health care providers
    • For reasonable accommodations at work/school
    • For necessary breaks in your day

Functional Gains

With resources in place, appropriate providers, and hard work, these foundational oculomotor deficits can get better through remediation-based therapy. Always set goals on function – how these deficits impact  a person on a daily basis – and always work toward that goal! With the help of a therapist, keep goals SMART- Specific, Measurable, Attainable, Relevant, and Timely. Remediation based therapy can be a long process, however there is hope for improvement and progress.

Kara Christy, MS, OTRL, CBIS, is an Occupational Therapist at Origami Rehabilitation. Origami is a 501(c)(3) nonprofit organization providing comprehensive rehabilitation for children, adolescents, and adults with neurological, developmental, mental health, and orthopedic conditions through their residential and outpatient programs. Learn more about Origami at OrigamiRehab.org or by calling 517-336-6060.