Tuesday, January 27, 2009

Many Persons with Hemianopic Vision Loss Can Safely Drive a Car

It's always unfortunate when you have to add insult to injury by revoking the driver's license of a person who has just lost part of their vision due to a stroke, brain tumor, or other intracranial disease.

It is not at all uncommon to have these people tell you that although they realize they have lost part of their vision, they they are safe, careful drivers and they should be allowed to continue to drive.

It has always been my belief that although these people may think they are still capable of driving, they have, in fact, lost the left or right half of their vision in each eye (known as a hemianopia) and are probably a danger to themselves and others if they were to get behind the wheel of a car.

Then comes along a research paper (in the February edition of Investigative Ophthalmology and Vision Science) that confirms what the patient has claimed all along - that they can safely drive a car.

The researchers took 30 patients with hemianopsias (22 complete, 8 partial) and 30 normal-sighted persons for a 14 mile test drive through city and highway traffic. The vehicle was student driver equipted (extra brake) and the person riding shotgun was a certified driving rehabilitation specialist. Two "back-seat" evaluators who didn't know if the driver was normally sighted of had a hemianopic vision defect independently graded driving performance using a standard scoring system.

Using this test system, 73% (16/22) of drivers with a complete hemianopic defect and 88% (7/8) of drivers with a partial hemianopic defect received safe ratings from the back-seat graders.

The researchers concluded that some drivers with hemianopia are fit to drive. These results call into question the fairness of governmental policies that categorically deny licensure to persons with hemianopia without the opportunity for on-road evaluation.

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