Astigmatism is a common vision problem that causes distortion and blurriness when viewing objects at near or far distances. People with long-sightedness or short-sightedness often also have astigmatism, or astigmatism can occur by itself.
Astigmatism tends to cause blurring in one direction only - as if you have jolted your hands slightly while taking a photograph, but your vision is constantly like this. As most people with astigmatism are used to a little blur, they may not even know they have it.
Astigmatism is usually caused by the genes you inherited from your parents. Just as genes determine the shape of your nose, they also determine the shape of your cornea at the front of your eye and the lens inside your eyes. If the curve of the cornea or lens is not perfectly round but is shaped more like a football, astigmatism will result.
Astigmatism is not an eye disease and can usually be treated easily with spectacles or contact lenses. It is rarely serious but can cause eyestrain and reduce productivity. Occasionally, astigmatism can be related to eye conditions such as cataracts and keratoconus.
People with moderate to severe astigmatism usually notice their blurred vision. Slight degrees of astigmatism may cause headaches, fatigue, eye strain (especially at the computer) and reduced concentration. Astigmatism is often more noticeable at night as its effect is increased with larger pupils in dimmer light. People with astigmatism commonly notice flare or a doubling effect from streetlamps and headlights.
Only a thorough eye examination can confirm the presence of astigmatism. Once diagnosed, it usually remains stable or increases slightly with age.
You should consider being checked for astigmatism is any of the following apply to you:
Even if you have astigmatism, you may not need treatment, depending on your symptoms, or you may need to wear spectacles or contact lenses only for particular tasks, like driving at night or working on the computer. Your optometrist can advise you on your best options.