Astigmatism is a minor condition of the eye that causes blurred vision. It occurs when the cornea is not a perfectly curved shape. Most people who wear glasses have astigmatism.
The cornea and retina
The cornea is the transparent layer of tissue at the front of the eye. The cornea should be shaped like a football, but in cases of astigmatism it has an irregular curve, shaped more like a rugby ball. This means that the light rays that come into the eye do not focus properly on the retina and create a blurred image.
The retina is the light-sensitive tissue at the back of the eye where the light that enters the eye is converted into electrical signals. The optic nerve sends the signals to the brain, which interprets what is being seen. See Astigmatism - causes for more information about how the eye works.
Refractive errors
Astigmatism belongs to a group of related eye conditions known as refractive errors. Other common refractive errors include:
How common is astigmatism?
Astigmatism is a very common eye condition. It can be present at birth (congenital). However, it sometimes develops after an injury to the eye or as a side effect of an eye operation.
Outlook
In many cases, the symptoms of astigmatism are so mild that no treatment is needed to correct your vision. In cases where your vision is significantly affected by astigmatism, glasses or contact lenses can be used to correct it.
Laser treatment can be used to treat astigmatism in adults. However, it is unlikely that you will be able to receive laser treatment through the NHS.
