What is Astigmatism?
Astigmatism is a focusing error which causes asymmetric blur. Some directions of an image are more out of focus than others. This is different to short-sightedness (Myopia) where all directions are blurred evenly.
What causes Astigmatism?
Most Astigmatism is caused by the irregular shape of the front surface of the eye (the cornea). It can also be caused by slight tilting of the lens inside the eye. It may be an inherited characteristic or a normal variation accompanying growth.
How does Astigmatism affect me?
Astigmatism causes different amounts of blur in different directions. This causes images to appear distorted, or sometimes even double. Even slight degrees may encourage headaches, fatigue and reduce concentration. The eyes may try, without success, to correct the blur. These is also a tendency to squint the eyes to try to see better, producing discomfort in the muscles of the eyelid and face.
How is Astigmatism corrected?
Spectacles and contact lenses (hard and soft) can correct Astigmatism. Sometimes correction of Astigmatism can cause a change in the apparent size and shape of objects and may affect judgment of distance. A patient may feel taller or shorter, or walls and floors may appear to slope and curve.
In most cases, adjustment to these side effects takes only a week or so. Astigmatism correction may involve a compromise between optimal clarity and visual discomfort.
How is Astigmatism detected?
Some people notice blur themselves. Only a proper eye examination will determine for certain if you have Astigmatism. Astigmatism is not an eye disease and any changes are generally gradual and not necessarily for the worse. Most people have at least very slight Astigmatism.