Eye Care
Myopia
Myopia is the scientific name for what most people call short-sightedness.
Around 15 per cent of Australians are myopic. Without properly prescribed glasses or contact lenses they find it difficult to see distant objects clearly.
Short-sighted people find it hard to read road signs or score boards and cannot recognise people in the distance. Understandably, uncorrected myopia can have a destructive impact on studies, work and play.
In simple terms, myopia is caused by a change in the focal length or shape of the eye. Prescription lenses are the only sure way to correct myopia.
Contact lenses and spectacles are both good options for myopia.
Presbyopia
Presbyopia, or difficulty seeing clearly at reading distance, is a very normal part of ageing, like greying hair - only more frustrating.
Between the ages of 40 and 45 most people start to notice problems seeing close objects. Activities such a reading and sewing become difficult. People with presbyopia often find they hold their books and newspapers further away from their eyes in an attempt to make the print clearer. The common comment is that 'my eyes are fine, it's just my arms aren't long enough!'.
Apart from creating difficulty in reading, presbyopia may also cause sore eyes, headaches and tiredness as a result of close work.
Although the problems associated with presbyopia appear to come on suddenly, the ageing process behind presbyopia is gradual.
Our eyes are normally focused for distance vision. Inside the eye, there is a lens about the size of a pea. To focus on close objects, a special muscle changes the shape of this lens. As a normal part of ageing, the lens loses its flexibility and is less able to change its shape, making focusing on close objects more difficult.
By examining your eyes, an optometrist can prescribe a lens that will make near objects clear again. A number of correction options are available for presbyopia, including contact lens options.
Your optometrist can help you determine which corrective lens will suit you best. Presbyopia generally increases between the ages of 45 to about 65, when it levels. Because vision changes occur most significantly between 45 and 65, it is wise to have your eyes examined once every two to three years, not only to review your lens prescription but also your general eye health.
Hyperopia
Having difficulty focusing on near objects, but achieving clear distance vision is a common visual complaint. Hyperopia is commonly known as long-sightedness and affects young and old alike. A hyperopic person may have normal vision and even pass an eye chart test, but they find near objects appear blurred or have difficulty focusing close-up. As a result they may get tired eyes and headaches, which have a detrimental affect on reading, school and work.
A typical hyperope will get sore eyes and headaches from reading. Either they struggle to focus on the page or they cannot see the words clearly. Both problems cause strain.
Long-sightedness can be treated in a number of ways. Younger hyperopes may be given eye exercises or glasses for close work such as reading or studying. Older hyperopes and those with greater degrees of long-sightedness are more likely to need glasses for reading and possibly also for distance vision. Vision can also be corrected by contact lenses.
Astigmatism
Astigmatism is a focussing error that causes objects at both near and distance to be blurry.
Astigmatism is caused by the shape of the front of the eye (the cornea). Without astigmatism, the cornea is perfectly spherical, like the surface of a basketball. Light is focussed to a single point.
With astigmatism, the cornea is more oval, shaped like the surface of an egg, or a football. This causes light to be focussed in two different locations, meaning there is no single point of focus and the image is blurred.
As the eye cannot focus the two points, objects at all distance can be blurred or indistinct. Even small amounts of astigmatism may cause headaches, fatigue and reduce concentration. This is because the eyes will try, unsuccessfully to correct the blur, and there is a tendency to screw up the eyes to see better, resulting in discomfort in the eye and face muscles.
Astigmatism can be corrected by spectacles and contact lenses.
Astigmatism can be found in combination with short sightedness and long sightedness.
Cataracts
Cataracts, a cloudiness in the lens of the eye that can cause blindness, are easily and safely removed. Cataracts are usually a result of ageing, although they are occasionally caused by injury or disease. Most people over 65 have signs of cataracts.
Cataracts usually develop slowly and painlessly, progressively reducing useful vision. Symptoms include blurred or hazy vision, seeing spots, double vision and increased glare sensitivity. At first cataracts are characterised by misty 'veiling' vision and loss of contrast. At this stage an optometrist can often prescribe new glasses to help.
As vision worsens, reading gets slower and driving becomes difficult toward sunset. When glasses will no longer help, an optometrist will refer their patient to an eye surgeon to have their cataracts removed.
Cataract surgery is often performed under local anaesthetic, and the patient may be able to go home the same day. This relatively minor surgery removes the cloudy lens, allowing light to again pass freely to the retina. In most cases, the lens is replaced with an intra-ocular lens implant, a plastic lens surgically fitted inside the eye.
While patients may need to wear glasses or contact lenses after cataract surgery, in most cases their vision is better after the operation than before it.
Glaucoma
Optometrists are often the first people to detect a vision damaging condition, providing the front line of help for a range of vision disorders.
Because conditions like glaucoma often develop slowly and painlessly, they are often first noted by an optometrist when their patient undergoes a routine eye examination. When vision is reduced because the nerve cells that carry information from our eyes to our brain are damaged, we have what is known as glaucoma.
The condition is often associated with an accumulation of fluids in the eye, the resultant pressure causing the damage. Because it usually occurs in people over the age of 40 years and often runs in families, optometrists recommend these people have regular eye examinations. Although damaging, modern examination techniques and treatment have made glaucoma a rare cause of blindness in Australia.
The condition often develops unnoticed. There may not be any symptoms until it is too late, although sometimes people experience blurred vision, seeing coloured rings around lights, loss of side vision and sore, red eyes.
Optometrists can painlessly diagnose glaucoma by looking at the nerve fibres in the back of the eye, measuring the pressure in the eye, and by testing side vision with an instrument called a perimeter. Initially eye drops and medicines can treat glaucoma and in some cases surgery may unblock the errant drainage system in the eyes.
Diabetes
Around 420,000 Australians, or 2.5 per cent of the population, have diabetes. Of these, almost one in three suffers some form of damage to their vision, a condition known as diabetic retinopathy. Optometrists play a fundamental role in diagnosing these conditions in their early stages, when they respond best to treatment.
Diabetes sometimes causes the focusing ability of the eye to weaken or to fluctuate from day to day. This characteristic often has led to optometrists diagnosing diabetes in their patients. The problem eases when blood sugar levels are controlled by a doctor.
After diabetes has been present for some years changes may occur at the back of the eye in the retina. These changes are known as diabetic retinopathy. There are two types of this condition, background (sometimes called simple) retinopathy, and proliferative retinopathy.
The eye disease glaucoma is slightly more common in diabetics than in non-diabetics. Glaucoma is a condition in which the nerve cells that transmit information from the eye to the brain become damaged, often caused by an accumulation of fluid in the eye. Untreated glaucoma can cause tunnel vision and blindness.
Cataracts are more likely to occur in diabetic people at an earlier age than in non-diabetics. A cataract is a cloudiness that can form in the lens inside the eye.
Glaucoma and cataract are readily detected at your regular eye examination. It is advisable for all diabetics to have annual eye examinations. People with retinopathy should have eye examinations more frequently than once a year.