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One of the hardest questions eye care professionals deal with every day is when to tell people who are having difficulty with their vision that they need to stop driving.

Giving up your driving privilege is one of the most difficult realities to come to terms with if you have a problem that leads to permanent visual decline.

The legal requirements vary from state to state. For example, in New Jersey, the legal requirement to drive, based on vision, is 20/50 vision or better with the best correction in one eye for a “pleasure” driving license. For a commercial driving license, the requirement is 20/40 vision or better in both eyes.

In some states, there is also a requirement for a certain degree of visual field (the ability to see off to the sides).

According to the Insurance Institute for Highway Safety, the highest rate of motor vehicle deaths per mile driven is in the age group of 75 and older (yes, even higher than teenagers). Much of this increased rate could be attributable to declining vision. There are also other contributing factors such as slower reaction times and increased fragility but the fact remains that the rate is higher, so when vision problems begin to occur with aging it is extremely important to do what is necessary to try to keep your vision as good as possible.

That means regular eye exams, keeping your glasses prescription up-to-date, dealing with cataracts when appropriate, and staying on top of other vision-threatening conditions such as macular degeneration, glaucoma, and diabetes.

It is our responsibility to inform you when you are no longer passing the legal requirement to drive. Although there is no mandatory reporting law in all states, it is recorded in your medical record that you were informed that your vision did not pass the state requirements to maintain your privilege. And, yes, it is a privilege -- not a right -- to drive.

If you have a significant visual problem and your vision is beginning to decline, you need to have a frank discussion with your eye doctor about your driving capability. If you are beginning to get close to failing the requirement you need to start preparing with family and loved ones about how you are going to deal with not being able to drive.

Many of us eye doctors have had the unfortunate occurrence of having instructed a patient to stop driving because of failing vision, only to have him ignore that advice and get in an accident. Don’t be that person. Be prepared, have a plan.

Article contributed by Dr. Brian Wnorowski, M.D.

The content of this blog cannot be reproduced or duplicated without the express written consent of Eye IQ. This blog provides general information and discussion about eye health and related subjects. The words and other content provided in this blog, and in any linked materials, are not intended and should not be construed as medical advice. If the reader or any other person has a medical concern, he or she should consult with an appropriately licensed physician.

Who is Charles Bonnet?  He was a Swiss naturalist, philosopher, and biologist (1720-1793) who first described the hallucinatory experiences of his 89-year-old grandfather, who was nearly blind in both eyes from cataracts.   Charles Bonnet Syndrome is now the term used to describe simple or complex hallucinations in people who have impaired vision.  

Symptoms

People who experience these hallucinations know they aren't real.  These hallucinations are only visual, and they don't involve any other senses. These images can be simple patterns or more complex, like faces or cartoons.  They are more common in people who have retinal conditions that impair their vision, like macular degeneration, but they can occur with any condition that damages the visual pathway.  The prevalence of Charles Bonnet Syndrome among adults 65 years and older with significant vision loss is reported to be between 10% and 40%.  This condition is probably under reported because people may be worried about being labeled as having a psychiatric condition. 

Causes

The causes of these hallucinations are controversial, but the most supported theory is deafferentation, which is the loss of signals from the eye to the brain; then, in turn, the visual areas of the brain discharge neural signals to create images to fill the void.  This is similar to the phantom limb syndrome, when a person feels pain where a limb was once present.  In general, the images that are produced by the brain are usually pleasant and non-threatening.

Treatment and prognosis

If there is a reversible cause of decreased vision, such as significant cataract, then once the decreased vision is treated, the hallucinations should stop.

There is no proven treatment for the hallucinations as a result of permanent vision loss but there are some techniques to manage the condition.  Give these a try if you have Charles Bonnet Syndrome.

• Talking about the hallucinations and understanding that it is not due to mental illness can be reassuring.
• Changing the environment or lighting conditions.  If you are in a dimly lit area, then switch on the light and vice versa. 
• Blinking and moving your eyes to the left and right and looking around without moving your head have been reported as helpful.
• Resting and relaxing.  The hallucinations may be worse if you are tired or sick.
• Taking antidepressants and anticonvulsants have been used but have questionable efficacy. 

Over time, the hallucinations become more manageable and can decrease or even stop after a couple of years.

If you experience any of these symptoms, please get evaluated by your eye doctor to make sure there is not a treatable eye condition.  Don’t be embarrassed or ashamed—your issue is likely caused by a physical disturbance and we are here to help!

Article contributed by Jane Pan

The content of this blog cannot be reproduced or duplicated without the express written consent of Eye IQ.