In the state of California, there are victims of traumatic brain injury who often suffer from visual impairments or blindness as a result of that injury. In fact, it is estimated that 20 to 40 percent of victims of brain injury suffer from some type of vision disorder.
When it comes to traumatic brain injury, there are two general types of visual problems. The first is visual acuity loss. This type of loss occurs when the nerve fibers carry signals from the eye to the visual cortex. The loss can, at times, be effectively treated with electronic reading aids, magnifiers, or eyeglasses. The amount of loss will determine how the patient’s life is impacted. In minor cases, the patient can be compared to a typical person who requires bifocals.
The second type of vision disorder is visual field loss. This type of injury is more complicated than visual acuity loss. If you think of your vision as a pie, visual field loss occurs when a piece of the pie is affected. Some patients suffer from hemianopsia, where half of the visual field is eliminated. Others experience a visual loss in a quarter of the field, called quadranopsia. Homonymous hemianopsia is when the same half or quarter field of vision is lost in both eyes at the same time. Bitemporal hemianopsia is when the outer or inner half of the visual field is missing in both eyes.
Just as each patient is unique, so is blindness that occurs with a brain injury. The damage may be treatable and temporary. In some cases, vision loss is permanent. In other cases, the visual loss may worsen over time.
