What effects does traumatic brain injury have on the visual system?
- Focusing problems – A reduction in eye focusing ability results in blurry vision at near, even in young athletes. Near vision may be constantly blurry or may pulse in and out of clarity during near activities.
- Blurry vision – Blurry vision following a concussion can occur at distance, near or both.
- Convergence insufficiency – This inability to use the eyes comfortably at near can result in a number of symptoms including: headaches, eye strain, fatigue or even double vision during near activities.
- Double vision – Anyone who sees double (even intermittently) should be evaluated by an optometrist with advanced training in neuro-optometry, binocular vision and vision therapy.
- Light sensitivity – Photophobia, or light sensitivity, can result from various types of acquired brain injuries (including concussions).
- Ocular-motor dysfunction – Deficiencies in eye movement abilities are quite common following concussions and other forms of mild traumatic brain injuries. These eye movement deficits can pose challenges with many activities of daily life, including reading and driving. Oculomotor dysfunction can cause dizziness and vertigo symptoms as well, which can significantly impact a patient’s quality of life.
- Balance problems – After a head trauma, a patient’s awareness of their “center” can be shifted. This is called an egocentric localization shift. It can cause a patient to lean or fall forward, backward or to the side. Special lenses may be needed to improve the patient’s balance.
Reduced cognitive abilities with visual tasks
- Visual discrimination – Seeing small detailed differences between objects
- Visual memory – Keeping a visual image in your head in order to retain information better
- Visual sequential memory – Remembering a sequence of information, like a phone number, or several items on a to-do list
- Visual figure ground – Finding objects in a crowded area, working with spreadsheets on a computer. Crowded stores and restaurants can be overwhelming also.
Reduced visual processing speed or reaction time
- reading the field of play
- judging the speed of a moving ball or puck
- judging the speed of other players on the field
Visual information overload
Due to the neuroplasticity of the brain, patients can still benefit from treatment even several years following a head injury.