Stephanie Schmid, an occupational therapist at On With Life, discusses how vision can be affected following a brain injury.
Q: Why is vision often impacted after a brain injury?
A: When most of us think about vision, we think of visual acuity (our ability to see things clearly). Eye glasses and contact lenses change visual acuity by adjusting where the incoming image meets the retina at the back of the eye. A brain injury often causes damage to the components of the visual system that are located within the brain rather than the eye itself. The visual system is complex as information from the eyes has to travel on pathways from the front of the brain, around and to the back of the brain to the occipital lobes. This complexity makes vision vulnerable to damage because of the high probability of a brain injury impacting/damaging the tracts at any point along those pathways. In addition, cranial nerves in the face can be damaged when a traumatic brain injury occurs. As a result, eye muscles may not align correctly, the eyelid(s) may be closed and unable to open, an eye may be turned inward or outward, or the pupils may be different sizes.
Q: What are frequent vision problems to watch for following a brain injury?
A: Diplopia (Double vision) is one of the most common challenges associated with cranial nerve damage and eye coordination difficulty. Each eye sends an independent image on its pathway to the back of the brain where the information from the two eyes combines to form one image. If the eyes are aligned poorly, the brain cannot combine the information to form one image. A visual fieldcut is also common when the pathways from the eyes to the brain are damaged. In cases of fieldcut, the brain isn't able to process information from a portion of each eye's visual field. As a result, the individual might miss a small portion of or the entire right, left, upper or lower portion of their vision.
Q: What should I do if I or a loved one is experiencing vision changes following a brain injury?
A: If vision therapy is needed, On With Life's occupational therapists have the clinical knowledge, expertise and technology to help. We also recommend an evaluation by an optometrist who has experience in neurologic vision challenges. In collaboration with these physicians, therapists at On With Life develop an individualized and specific vision plan which may include eye exercises, activities to build eye strength/ coordination and compensatory devices such as prisms to improve eye coordination and align the eyes. Vision therapy is available at On With Life on an inpatient and outpatient
basis.