What is astigmatism?
Astigmatism is a common condition which causes blurred or distorted vision. It occurs when the cornea or lens is not a perfectly curved shape, leading to a refractive error. There are two different types of astigmatism:
- Regular astigmatism – This is the most common type of astigmatism, and it occurs when the cornea is curved slightly more in one direction than the other.
- Irregular astigmatism – This type of astigmatism is less common, and is often the result of an eye injury. The different curves of the cornea are not at right angles to each other (as they are in regular astigmatism), and as such the cornea isn’t curved evenly.
Most people with astigmatism have short-sightedness
as well. In most cases, the symptoms of astigmatism are mild, but if you find that it’s causing problems it’s important to get it corrected in order to avoid straining your eyes.
What are the symptoms of astigmatism?
Symptoms of astigmatism can vary from one person to another, but may include:
- Blurry or distorted vision, both close-up and at a distance
- Eye strain
- Tiredness, particularly after tasks such as reading or using a computer
- Difficulty with night vision
Astigmatism is usually diagnosed during an eye test, so it’s important for both children and adults to attend regular check-ups.
What causes astigmatism?
Astigmatism usually occurs when the cornea or lens has got an irregular shape. The cornea should have a regular curve, a bit like the shape of a football, but for people with astigmatism the cornea’s curve is more like a rugby ball. This means the cornea can’t focus light rays properly, resulting in blurred vision.
The majority of people with astigmatism are born with it, but it can also develop in later life, for example as the result of an eye injury or surgical complication. Factors which could increase your risk of developing astigmatism include:
- A family history of astigmatism or other eye conditions such as keratoconus
- A high degree of short-sightedness (myopia)
- A high degree of long-sightedness (hyperopia)
- Having had some types of eye surgery, such as cataract surgery
- Scarring or thinning of the cornea, for example if an eye injury has scarred over
How can astigmatism be treated?
In mild cases of astigmatism, treatment may not be necessary, but in more severe cases you could use glasses or contact lenses, or have laser eye surgery to correct your vision permanently. Intraocular lens implants used in refractive lens exchange or cataract surgery are also available in toric form to correct astigmatism.
If you have irregular astigmatism, you won’t be able to correct it with glasses, so if wearing contact lenses isn’t for you, laser eye surgery could be a great option.
At Optegra, we offer LASIK, LASEK, SMILE and lens implant eye surgery methods, all of which can be used to treat patients with astigmatism.