Visual field loss, or loss of peripheral vision, causes a significant functional limitation on vision. People suffering from visual field loss will often times bump into objects, miss things to the affected side, and even miss half of the food on their plate. Driving is frequently given up and thought to be out of the question.
Visual field loss occurs with damage to the visual portions of the brain and with the nerve connections between the eyes and brain. There are many forms of visual field loss, with many causes and some effective compensatory treatments.
Hemianopsia refers to a loss of one half of the field of vision either right, or left. Each eye loses vision to the affected side. Altitudinal visual field loss refers to a loss of the upper or lower field of vision of both eyes. Quadrantanopsia refers to a loss of one quarter of the field of vision. The right side of the brain affects left side of vision, and visa versa. With true visual field loss the person knows they donít see to the affected area.
Visual neglect is a perceptual loss, or unawareness of vision. Typically the right parietal cortex is involved causing a left visual neglect. The parietal cortex is the visual association cortex. It takes visual input from the occipital cortex and other areas, and assembles it into meaningful information. People with visual neglect lose the concept that the world exists to their affected side. The affected person is not aware of the loss of vision.
Causes of visual field loss, or neglect include: head injury, stroke, aneurysm, hemorrhage, brain tumor and anything else that affects the function and structure of the brain.
In the past there was little help to offer people with visual field loss. They were frequently told to just look to that side, or learn to live with it. Fortunately today because of work and research by Dr. Politzer and his colleagues effective solutions have been developed.
Field awareness systems are optical devices made of lenses and prisms. A special prism is manufactured in an eyeglass frame and positioned to the outer area of the visual field loss. The patient is trained through a program of vision rehabilitation to scan into the prism. A prismatic shift makes objects that are to the field loss side appear more in front. When used properly, the prism system can add up to 20 degrees of additional field awareness.
Vision rehabilitation is a systematic program of therapy to help people compensate for visual field loss. Exercises are done to improve scanning, maximize use of the remaining vision and overcome neglect.
Driving with a visual field loss is a difficult process. For some, however, by combining the prism system for increased field awareness, vision rehabilitation, and driver assessment and training, it can be achieved. There are very few certified driving programs. Dr. Politzer is on staff at Spalding Rehabilitation Hospital where there is a driving program. Feel free to contact Dr. Politzer for more information.