Astigmatism Explained

If you have been told that you or a family member suffer from a condition known as astigmatism or believe you might, you’ll no doubt want to know more about what it is and what it means for you. Read on to find out more.

What is astigmatism?

Astigmatism is a commonly occurring sight problem that causes blurry vision, often occurring alongside shortsightedness (Myopia) and farsightedness (Hyperopia or Presbyopia), which are all types of refractive error. Refractive error vision problems occur when the shape of the eye, or parts of the eye, prevents light from being focussed correctly, resulting in varying degrees of blurry vision. 

What causes astigmatism?

The light-receiving surface of an eye consists of several layers; the clear outer layer called the cornea, through which light travels into the lens which sits behind the pupil. The lens focuses the light onto the retina at the back of the eye which in turn then sends signals to the brain to process it as information on what we can see. All of these layers should be curved evenly, like a round ball, with all the layers following a similar curve. 

Astigmatism occurs when either the cornea or the lens are shaped differently; instead of being a round curve like a regular ball, they are more oval like a rugby ball. Because of this, light rays entering the eye are not correctly directed to the retina. Instead, the light rays bounce too far in front or behind the retina, causing blurry vision. 

There are two main types of astigmatism; if it is the cornea that has mismatched curves then it is called corneal astigmatism, if it is the lens then it is known as lenticular astigmatism. 

Astigmatism is usually present from birth, although changes in the eye caused by injury, surgery, disease or ageing can also cause it later in life. Most people with astigmatism are usually also either shortsighted or farsighted. As it is thought to be caused by genetics, it cannot be caused by too much reading, looking at screens or similar actions.

What are the symptoms of astigmatism?

The symptoms are mainly blurred, fuzzy or distorted vision. This may just be in small patches, in any direction, or it could affect the whole image seen through the eye. If not properly treated, the extra effort and concentration needed to see can cause headaches, squinting, eye strain or tiredness and irritated eyes. Vision in low-light and at night may become difficult. 

Astigmatism in children can be a factor in the vision problem known as lazy eye (Amblyopia). If left untreated it may affect their concentration and their ability to do close work, such as reading and writing. 

How is astigmatism treated?

There are currently three options available to treat astigmatism:

  • glasses
  • contact lenses
  • laser eye surgery

Not every option will be suitable for every individual and they are not all available through the NHS. 

The first step in getting astigmatism corrected is to have a thorough eye examination carried out by an optometrist who will assess and then discuss the most suitable treatment options. 

Book an appointment today

If you have concerns about your eyesight or wish to book an eye examination, call the experts at Sergeant & Barber today on 01502 568241.

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