Myopia

Inability to see distant objects clearly, commonly known as shortsightedness

  • Usually becomes apparent around puberty
  • Sometimes runs in families
  • Gender and lifestyle are not significant factors

To enable us to see clearly, light rays need to be focused by the transparent cornea at the front of the eye and by the eye’s lens so that they form a sharp image on the retina, the light-sensitive membrane at the back of the eye. In people who have myopia (shortsightedness), the eyeball is long relative to the combined focusing power of the cornea and the lens. Light rays from distant objects are therefore bent too much and are focused in front of the retina, resulting in blurred vision. Myopia is a very common condition that sometimes runs in families and can usually be corrected.

Myopia

In myopia, the eyeball is too long relative to the focusing power of the cornea and lens. Light from distant objects is focused in front of the retina and the image is blurred.

What are the symptoms?

The symptoms of myopia often become apparent around puberty, but the condition may begin to develop a few years before. The earlier myopia starts, the more severe it is likely to become. However, the condition usually stabilizes in early adulthood when growth stops. The main symptoms are:

  • Increasing difficulty with distance vision.

  • In children, deteriorating schoolwork as a result of not seeing clearly.

If you are seriously myopic, you are more susceptible to eye disorders such as retinal detachment, chronic glaucoma, and macular degeneration. All of these can badly damage eyesight. If you have problems with distance vision, you should visit your optometrist.

What might be done?

The optometrist will carry out vision tests to check for myopia. Myopia can be corrected with concave-lensed glasses or, for older children and adults, contact lenses (see Glasses and contact lenses). In mild to moderate cases, the cornea’s shape can be altered by surgery to correct vision (see Surgery for refractive errors).

From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.

The subjects, conditions and treatments covered in this encyclopaedia are for information only and may not be covered by your insurance product should you make a claim.

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