How sickness can affect driver safety

By Stefan Weissenborn Jan 31, 2011, 3:06 GMT

Frankfurt - Top performance is only possible when you are top fit. That maxim applies both to athletes and motorists as health problems can reduce your ability to drive and thus increase the risk of an accident occurring.

Eyesight complaints play an important role - especially at night. 'Even healthy eyes can reach their limit at night time,' says Hannelore Hoffmann-Born from the German Society for Traffic Medicine.

If a motorist is relatively young, weak eyesight can usually be compensated for with the aid of spectacles or contact lenses, according to Hoffmann-Born. But as age rises, eyesight problems get worse, which can lead to a situation that cannot be dealt with by conventional medical techniques.

'Elderly people are more easily dazzled by light,' according to one example cited by Hoffmann-Born. An affected person does not properly register the lights of an approaching car. Instead they see the light as if through a translucent pane of glass. Cataracts or illnesses of the cornea, lens or vitreous humor can also affect nighttime vision.

If you are aware your eyesight has been affected then you should drive more defensively than recommended or even stop driving at night altogether. According to Germany's ADAC motoring association, about a third of all over 70-year-olds are no longer capable of driving safely at night even if they are not susceptible to dazzling light.

'I've driven for years without having an accident,' - that's a phrase often used by people who are no longer fully fit to sit behind the wheel of a car. But it's one that Hoffmann-Born says should not be allowed to apply. 'You notice yourself that your vision is deteriorating,' she says.

There is no alternative to getting the opinion of an optician who can determine whether a patient is able to see well at night. Other issues they might detect include the failing ability to define colours, which is called Protanopia and Protanomaly.

If you cannot properly recognise the red light of a car's brake lights then your chances of experiencing an accident are higher.

Almut Schoenermarck is a doctor who works for the ADAC. Along with Hoffmann-Born he favours the introduction of mandatory eyesight tests every 10 years for all motorists up to the age of 50, every two years up to 60 and every year after that.

t the moment there is no obligation of this kind in Germany where driving licenses are awarded for the span of the motorist's lifetime. A doctor's certificate of good eyesight must be provided when applying for a license originally.

Along with bad eyesight, other health issues can affect drivers. They are often quite difficult to detect - even for doctors. Schoenermarck says that 'a GP can often be overwhelmed by the question as to when a patient can begin driving again after being in hospital for a heart attack, for example.'

Many doctors are also not aware that they must inform their patients about possible driving restrictions that may affect them.

Drivers that suffer from diabetes, psychiatric disorders, and cardio-vascular disease also need to be aware there are limits to their driving abilities.

A diabetic can suddenly become unconscious behind the wheel of a car if their blood sugar levels fall too low. Some forms of psychiatric disorders leave their sufferers very tired during the day. Manic depressive patients can often endanger themselves and other drivers by overestimating their abilities.

Schoenermarck believes a doctor trained in traffic medicine is the best person to say whether a patient should return to driving after an illness. Some medicines can help to reduce the risk for people suffering from high blood pressure, diabetes or mental illness. Schoenermarck recommends seeking the advice of an expert.

As a general rule, however, you should be aware that many types of medicine can limit your driving ability, according to Hoffmann-Born.

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