March is brain injury month. Eyesight is the human brains most sophisticated sensory system. About 50 percent of brain injuries demonstrate visual skill deficiencies. There are two types of brain injury: traumatic brain injury (TBI) such as concussions and acquired brain injury (ABI) such as cerebrovascular accident or stroke. Visual symptoms exhibited include blurry and/or double vision, eye fatigue, headaches, loss of visual field, visual perception (visual spatial, figure ground, etc.) difficulty and eye tracking difficulty. Many of these visual symptoms can be treated and alleviated with vision therapy.
Patients who acquire double vision (diplopia) after brain injuries can have a paralysis of a nerve controlling the eye muscle, gaze restrictions from the mechanical stress of trauma or decreased eye teaming ability. Often prisms, lenses and/or vision therapy/rehabilitation can be used to improve a patient’s eye teaming ability by improving their compensating vergences (ability to turn eyes in or out). Worst case scenarios where patients cannot improve their eye teaming ability, occlusion is used to suppress one of the images.
In visual field defects patients are blind in certain field of views. Often, they can use prisms to shift the image in the effected field of view to scan the target. In vision therapy or rehabilitation, the patient can be taught how to scan that image and then shift their central vision to view it in more detail.
Brain injury patients can also have a visual balance disorder. An example of such is Visual Midline Shift Syndrome (VMSS). This can cause brain injury patients to have difficulty with eye tracking skills (oculomotor dysfunction). Difficulty controlling their eye fixation, pursuits (smooth eye movements) and/or saccades (jump eye movements) are often present. Lenses, prisms and vision therapy/rehabilitation can be used to alleviate symptoms.
Developmental Optometrists can greatly help in the rehabilitative process of the brain injury patient. If you or someone you know has had a brain injury and is experiencing visual discomfort, call us to make an appointment for a developmental eye exam. We will assess the visual skills discussed above and, if needed, create a vision therapy/rehabilitation program to improve the visual discomfort.