Look After Your Eyes
Written by: Simon Keightley,
Consultant ophthalmic surgeon
The eye is a wonderful piece of machinery. It allows you to appreciate the world’s beauty and live an independent life. Maybe that is why many people say that they would rather be deaf than blind.
The eye is a delicate organ; it is susceptible to several conditions which can be painful, and more worryingly, can affect the vision.
Like a car, another piece of machinery which most of us can’t do without, the eye needs regular check-ups to make sure everything remains in good working order.
The commonest problem to affect the eye is a difficulty reading when we reach the age of about 45, although some lucky people do not have this problem until much later. The reason for this is the muscles within the eye that alters the focussing mechanism of the lens become rather less efficient, just like muscles elsewhere in the body.
Unfortunately, unlike other muscles, it is impossible to train yourself to improve muscle function.
It is a source of frustration for many people in the prime of their lives not to be able to read the small print when they need to.
The simple remedy for this affliction is of course reading glasses. They will help the muscles within the eye to focus the newsprint, or whatever you happen to be looking at, to a more acceptable level. In addition a good light is very important; daylight is the best, but if not, a strong (100W) bulb or one of the newer halogen bulbs in a light which casts no shadow across the page works well. There is no truth in the rumour that using your eyes to excess damages them in any way.
Prolonged reading or using a computer screen may make them feel tired, but it will not cause any permanent damage. Reading glasses can be purchased over the counter in a number of shops and often these do work well and can be much cheaper than those prescribed for you by an optometrist. Nonetheless, a regular trip to an optometrist is a good idea, as he or she can give your eyes a good examination and screen for other problems.
There are those of us who have refractive errors and rely on glasses not just for reading. These problems are because of variations in the shape of our eyeball. Short-sighted people, or myopes, are unable to see in the distance but are very good at reading without the need for glasses. Such people have longer eyeballs than normal people, and often start to need glasses when they are at school. On the other hand, long-sighted people, or hypermetropes (hyperopes), can’t see up close whereas their distance vision is often reasonable. This is due to the eyeball being shorter than normal.
People with astigmatism often have indistinct vision at all distances. This is due to the front surface of the eye, the cornea, being curved in one direction rather more than the other. It is similar to the eye looking like a rugby ball rather than a football. All these conditions can be corrected with glasses of one sort of another, and the local optometrist will prescribe these appropriately. There are some people who believe that these refractive errors can be helped, if not cured by certain forms of eye exercises, thus removing the need for glasses. There is precious little scientific evidence that this is the case, but it is important to stress that glasses should not be worn unnecessarily.
Many of us with refractive errors now wear contact lenses. This certainly gets rid of the nuisance value of wearing glasses and often can give us a better quality of vision than glasses. They may, however, cause more problems to the eyes than glasses because they obviously touch the surface of the eye. New materials, such as the disposable soft contact lenses now available are very well tolerated and widely worn. It is important to be scrupulously clean when inserting and removing contact lenses. In addition, regular appointments with the optometrist are essential.
You have probably heard of the newer laser techniques for treating refractive errors of all kinds. Many such centres have sprung up and are widely advertised. All are run within the private sector because there are none within the National Health Service framework apart from a few with a research aspect.
All techniques rely on a method of reshaping the surface of the eye.
Initially this was using a knife wielded by a surgeon, but nowadays it is almost exclusively done using a computerised technique involving lasers. LASIK (Laser In-Situ Keratomileusis) is probably the most commonly used technique. This involves a flap of cornea being raised by the surgeon using a mechanical device, or more recently by a laser. Another laser is applied to the central underlying tissue to remove a precise amount of tissue and then the flap is replaced. Myopia of relatively low power is the most amenable for this type of treatment. The techniques are still evolving and with time it is likely that all forms of refractive error will be equally amenable to this form of treatment.
Tints and shades
The ultraviolet light produced by the sun, especially when it is reflected from white or shiny surfaces such as snow or rain soaked roads is extremely uncomfortable and may be dangerous.
Certainly skiers should wear suitable eye protection at all times when on the slopes as of course should welders and other workers exposed to intense forms of ultraviolet light. So when you are relaxing on a sun bed, whatever you do, wear your goggles – even if you end up looking like a panda!
Drivers who have a degree of cataract often don’t like driving in bright sunshine because of the glare from the sun. Driving with the sun visor down, or wearing a hat with a peak helps, but tinted glasses (or a pair of clip on sunglasses over your driving glasses) are almost a necessity.
Glaucoma is a serious eye disease which in the past caused a lot of blindness. The reason it is less of a problem these days is that optometrists pick it up early. It affects 1% of us over the age of 40, and it is commoner in people who have a family history of this condition. In the first stages of glaucoma there are no symptoms whatsoever, and so the unsuspecting person with it has no idea that they have a problem until they have had it for many a year. By then, there is often little in the way of treatment that can prevent eventual blindness. In the early phase, by contrast, treatment can often arrest the condition.
The problem with glaucoma is that the pressure within the eyeball becomes too high. This is nothing to do with blood pressure, but is because the fluid within the eye, which is constantly being produced and drained away, can’t escape from the eye efficiently. This is because, for some reason we know little about, the drains within the eye becoming blocked. The high pressure then damages the optic nerve which is the main connection from the eye to the brain, therefore reducing vision. Initially the part of the vision affected by this disease is the peripheral visual field, so some areas in your vision become less distinct.
The problem with glaucoma is that the pressure within the eyeball becomes too high. This is nothing to do with blood pressure, but is because the fluid within the eye, which is constantly being produced and drained away, can’t escape from the eye efficiently.
The central vision remains excellent until relatively late, and this is why many people don’t know they have got a problem until much later. This is why it is important for all people to visit an optometrist on a regular basis. They can simply check the pressure within the eye using a device called a non-contact tonometer. This sends a sudden puff of air into the eye and the pressure can be measured. This is a painless procedure, but it can certainly make you jump at the time. As glaucoma often runs in families, people who have a strong family history can get their eyes checked for free at the opticians once they are over 40 years of age. In addition free eyes tests are available to those over 60.
Most high-street optometrists cannot treat glaucoma but they can then refer you, via your general practitioner, to see an eye doctor at your local hospital. Here, the doctor will confirm the diagnosis and will then treat you usually with drops. These lower the pressure very effectively and the inevitable blindness is prevented. These drops are usually for life and you will need to attend the hospital eye clinic forever. In some areas of the country eye doctors work in collaboration with optometrists so eye checks can be done in the high street rather than in the local hospital. Sometime drops are not sufficient to reduce the pressure adequately, and then surgery or laser treatment can be used to good effect.
Cataracts are an increasing problem in our ageing population. It is the commonest cause of treatable blindness across the world and millions of people suffer from it. The problem lies in a bad design fault of the lens within the eye. As we age, the dead cells of the lens are compressed within the centre and this gradually causes cloudiness of the lens, thus reducing our sight.
The older we get, the cloudier the lens becomes and if we all lived long enough all of us would get cataracts in one form or another.
Again heredity plays a part and certain individuals are more susceptible to cataracts earlier than others. Diabetics are more susceptible to this problem also.
In the early stages of cataract, the symptoms are minimal; a common one is a glare or dazzle in bright sunshine or especially when driving at night where oncoming headlights are seen as starbursts of bright light. Reading can become more difficult, although most people say that their distance vision (for example watching the television) is more difficult than close work. The only treatment for this condition is surgery. Your optometrist is usually the first person to spot the problem and he will send you to the hospital eye clinic, again via your family doctor.
The surgery is often done under local anaesthetic and you will spend just a day or half a day in hospital. The surgery involves removing the lens with an ultrasound probe through a tiny (3mm) incision. A replacement lens is then inserted through the same incision. It is usually inserted folded up and unfolds inside the eye to resume the normal position of the lens. Stitches are not used in this type of cataract surgery. Distance after this procedure but reading glasses may well be needed.
Diabetes is a common disease which affects many parts of the body including the eye. It largely affects small blood vessels everywhere in the body and the small vessels in the eye are especially at risk.
All diabetics should have their eyes checked every year by an optometrist. Eye tests for diabetics are free to encourage this.
The examination will include examining the back of the eye to ensure that subtle damage is not occurring. If there is, then laser treatment may be necessary to seal the damaged blood vessels. This is carried out in the hospital eye clinic.
The eye is indeed a precious organ. Most of the time it works without us even thinking about it. When things go wrong it makes us appreciate how valuable our vision rally is. It is up to us to ensure our eyes are looked after well. Regular checks, at least every two years or more frequently if you are a diabetic, or have a family history.