Astigmatism is a common and treatable eye condition. It occurs when the surface of the cornea or crystalline lens is not spherical, giving an astigmatic eye more than one point of focus. This means that light from an object does not focus exactly on the retina, but at two separate points.
With curves that are steeper in one direction than the other, an eye with an astigmatism could have a cornea that is not spherical – shaped more like a rugby ball than football.
Many people have a small degree of astigmatism and their sight remains unaffected
In more severe cases, near or distant objects may appear blurred. You may also suffer from tired eyes or headaches while trying to focus.
People can be born with astigmatism, or it can occur later in life. Although it can develop after an eye injury, an eye disease or eye surgery, the exact cause is usually unknown, although genetics can play a part. What is certain is that astigmatism is not caused by using a computer, watching too much television or reading in bad light.
There are two types of astigmatism, regular and irregular. Irregular astigmatism is often caused by a corneal scar or ‘scattering’ in the eye’s crystalline lens. While this type of astigmatism can’t be corrected by standard prescription lenses, it may be corrected by contact lenses or, in minor cases, by laser eye surgery. Regular astigmatism, arising from either the cornea or crystalline lens, can be corrected by a toric lens.
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