The importance of eyesight to safe driving has been stressed by Melbourne ophthalmologist Dr Lewis Levitz of Vision Eye Institute who is encourages everyone to take his or her sight seriously when getting behind the wheel.
"Most of us know what the petrol capacity of our car is and what the tyre pressure should be. But most of us don't know what the minimum sight requirements are, which is a scary thought," he said.
There are two main legal requirements that need to be met for driving, said Dr Levitz.
· Visual acuity, or how well you can see for driving,,
· Visual field, which is how wide an area you can see in front of you.
But there are other factors that can influence driving and vision including:
· Depth perception;
· Lack of sleep;
· Visual distractions;
· Colour blindness;
· Double vision;
· Night vision problems.
"The problem with these is that there is no way to regulate them, said Dr Levitz who specialises in cataract,oculoplastic and general ophthalmology. "Some people, such as those who are colour blind, can learn to cope. Other factors such as lack of sleep are temporary and common sense is needed",
But serious diseases or disorders of the eye that affect vision can be diagnosed, and an ophthalmologist will be able to ascertain if a person is able to legally drive - or when it's time to stop.
Unfortunately, said Dr Levitz, unlike good wine, our eyesight does not improve with age.
Some issues with older drivers include:
· Cataracts. The ability to see street signs in the presence of oncoming traffic may be affected or the headlights of cars look like they have halos around them and look fuzzy. Glare also becomes an issue;
· Glaucoma. This can impair your ability to see to the side, so that pedestrians starting to cross the road or cars overtaking on the side may not be easy to spot.
· Macular degeneration. As this disorder develops, it becomes more difficult to adjust to the lighting conditions when driving from a brightly lit area into a dark one, such as into an underground carpark. The central vision may also get blurry and the street lines may look crooked or warped.
Most states now require drivers over the age of 75 to have regular medical assessments, where conditions that will affect driving are visual disorders, memory changes, cardiac conditions and diabetes can be monitored.
"You're most likely able to meet all the requirements to drive a car safely and will generally be aware of any circumstances in which your vision may be impaired while behind the wheel, but it is important to have your eyes checked regularly," said Dr Levitz.
