Driving With Visual Field Loss
- Visual field loss means that the normal amount of vision one experiences has become diminished or become lost altogether. Certain visual impairments such as glaucoma may steal a person’s peripheral vision and the person sees less to the side and begins to have a more central vision approach to life tasks, including driving.
- Macular degeneration often occurs with aging and affects loss of central visual field with peripheral vision usually remaining intact. Important information such as recognition of traffic lights or signs can occur if the deficit is significant enough.
- Other impairments such as a stroke, brain injury, or brain tumor may impede more specific aspects of a person’s visual field. For example, a person with a homonymous hemianopsia has loss of vision on one side of both eyes. If the center portion of the vision is not spared, the person cannot see past their midline to the side affected. This is a dangerous condition for driving as traffic situations cannot be interpreted in a timely manner on the “blind” side. Driving with a homonymous hemianopsia is precluded in North Carolina.
- A quadrantopsia is a condition where an upper or lower quadrant of the vision has been affected in the same area of both eyes. This is usually a more manageable visual deficit behind the wheel. However a formal driver evaluation is beneficial to assure adequate visual scanning occurs when driving. A person must diligently scan into the area of visual field loss to be safe in driving with a quadrantopsia. Customized mirrors can also be recommended to aid with driving safety.
- In any situation, a visual field loss can significantly impact safety behind the wheel and a driver evaluation is recommended to assure maximal visual efficiency when driving. Recommendations may be made for home exercises to learn to use residual vision more efficiently (visual multi-tasking), for behind the wheel training to increase vision skills when driving, or a referral to a vision specialist may occur.
Driving With Eyes That Don’t Work Together
- Some conditions such as cerebral palsy, spina bifida, or a brain injury may cause a disrupted visual system in which the eyes don’t work well together. This can result in double vision or may lead to a visual system that alternates which eye is “in charge” of processing vision. Often the effect of this on driving results in challenges with maintaining lane position or processing the driving environment in a timely manner. Many clients have learned to drive despite this visual challenge. A driver evaluation is critical to determine the best approach for each individual. Sometimes the eyes can be rehabilitated to work effectively. Other times a compensatory strategy is needed to aid in driver independence.