Short sight or 'myopia'

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What is myopia?

Myopia is the medical term used to describe a condition which allows people to clearly see objects which are up close to them, but not those at a distance. It is also called near-sightedness or short-sightedness.

Grouped together with hypermetropia (far-sightedness) and astigmatism (distorted vision), myopia is what is known as a refractive error.

In order for eyesight to work properly, the cornea (which is the clear 'window' in front of the eye) and the lens (which is positioned behind the pupil) must focus or refract light onto the retina at the back of the eye. Myopia is caused by the eye being too long from back to front and, therefore, images of distant objects are focused in front of the retina.

What causes myopia?

Very few factors outside of heredity affect myopia, so if there is a history of myopia in a particular family there is a very strong possibility that it will be passed on through the generations. It used to be thought that reading excessively, using dim light and certain nutritional deficiencies were all contributory factors to myopia, but there is no medical evidence to back up these claims.

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How is it detected?

Myopia is usually detected in children during routine eye examinations in national school. It tends to develop around puberty and increases until the early 20s, when it generally stabilises. Myopia that begins in early childhood often progresses into adult life and may become severe.

How is it treated?

Most eye doctors feel that the best treatment for myopia is either good eyeglasses or contact lenses. These compensate for the elongated shape of the eye and allow light to focus properly on the retina.

During their growing years, children and teenagers with myopia will need to change their eyeglasses or contact lenses on a regular basis (perhaps every six months) to keep pace with the growth of their eyes.

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Is surgery ever necessary?

Surgery is not usually recommended to correct myopia. However, there are a number of refractive surgery techniques available for those who would prefer not to wear eyeglasses or contact lenses. Among these are a technique called LASIK, which is commonly used in America, but has only recently been introduced in Ireland. Not all cases of myopia are suitable for Lasik treatment. If you are interested in this treatment, discuss it with your doctor who will refer you to an ophthalmologist for assessment. Another technique is called Radial Keratotomy, which involves surgery on the eye, but this is not widely used in Ireland either.

Since myopia which is detected in childhood usually levels off in adulthood, it is not considered to be sufficiently serious to warrant surgical intervention unless the patient specifically requests it.

Is myopia curable?

No, there is no specific cure for myopia. However, most people who suffer from near-sightedness can cope perfectly well provided they attend for regular eye check-ups and change their eyeglasses and/or contact lenses frequently.

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