WHAT CAN GO WRONG T here are a number of serious
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eye troubles that truck drivers themselves may face. Cataract problems can be treated directly vision starts to become impaired—the days when it was necessary for the cataract to become "ripe" have long gone.
The major cause of blindness is now termed "age-related macular degeneration". It used to be called "Senile macular degeneration" but this term was thought to be offensive to the old people it affected. The macula is the most sensitive area at the back of the eye and when it is damaged, vision straight ahead is diminished. Some treatments may help to arrest the progress of the disease. None can cure it. But as its old name of senile macular degeneration suggests, truck drivers would be unlucky to be affected during their working lives.
Another major cause of blindness is glaucoma. It is caused by trouble with the eye's drains. Fluid is produced in the eye but the outflow is insufficient. So the internal pressure in the eye goes up and this affects the operation of the delicate nervous mechanism of the eye. Once the condition is detected it can usually be controlled. If it advances, it can affect sideways vision.
Diabetes mellitis (sugar diabetes) is one general disease that can seriously affect vision and is sometimes first detected by changes in the appearance of the back of the eye. So is a brain tumour, but this is rare.
Other problems include "tunnel vision". This loss of side vision only occurs in severe occular disease. The most dramatic is the inherited disease of "retinitis pigmentosa". But if truck drivers have a full eye examination when they have their routine medical check-up, dire conditions should be detected in their early stages. So forget about "tunnel vision".
"Night Myopia" is better called "empty field myopia". When the eye has no detail to focus on, it does not completely relax. The effect on vision is small. When driving at night the view ahead is illuminated by headlamps on unlit roads. Most driving is on roads with street lighting when there is plenty of detail to focus upon. I have spent the whole of my adult life looking for this night myopia effect on the road and I am, as an ex-RAF pilot and later, photographic interpreter, a trained observer. I have looked assiduously and I have failed to detect it.
So, when an electronics engineer devises yet another machine for measuring the power of the eye (there have been many before and they have their limited uses), and then proclaims that it can produce an optical prescription specially for night myopia, I remain completely unconvinced. So forget about "night myopia".
"Myopia, hypermetropia and astigmatism." The traditional way of enabling people with these "refractive errors" to see clearly was to provide them with spectacles.
Various regimes of eye exercise have been devised by Americans since the 1920s. Dr WH Bates wrote "Better sight without glasses". His view that "one cannot have too much sun treatment" hardly accords with current thought. One of his champions, the writer Aldous Huxley, sadly, in the end went blind. .
Then later, after the Second World War, contact lenses gradually evolved into a practical alternative for workers such as truck drivers, always provided that reasonable precautions are taken.
The trouble with the higher orders of myopia is that it can go on increasing and the retina degenerates.
All manner of surgical techniques have been tried to modify the optical power of the eye. Currently lasers are being increasingly used. The interesting thing is to see by how much the eye "regresses" over the years, that is goes back towards its original power. Those whose livelihood depends on being able to see clearly might do well not to be at the head of the queue when new surgical procedures are being offered if they can obtain clear vision with ordinary spectacles.