WHAT IS ASTIGMATISM? CAUSES, SYMPTOMS & EYE TEST
Astigmatism is one of the most common eye conditions that can affect one or both eyes. Astigmatism can result in blurred or distorted vision at all distances. It can affect people at any age and often people with astigmatism are short-sighted or long-sighted too. In the UK, nearly half of the people who wear glasses for vision correction have astigmatism.
What causes astigmatism?
Astigmatism occurs when the surface of the eye (cornea)or the lens behind it is not a round shape, but oval like a rugby ball. This distorts the light entering the eye which does not focus correctly on the retina, and as a result the image is blurred.
What are the symptoms of astigmatism?
Astigmatism can cause blurred vision when you are trying to focus on objects at long distances, such as road signs. It can also affect your vision for close activities, such as reading or sewing. If left uncorrected, astigmatism can lead to:
- Eye pain
- Blurry vision
There are two types of astigmatism.
1. Regular astigmatism is when the cornea is curved more in one direction than the other. It is the most common form of astigmatism and can be corrected easily with glasses or toric contact lenses.
2. Irregular astigmatism is far less common and happens when the curvature of the cornea isn't even. It may be the result of an eye injury and related damage to the cornea, or a condition such as keratoconus, a progressive eye condition where the central cornea thins and becomes irregular in shape. It can't always be corrected with glasses, but it may be possible to correct with specialist contact lenses.
HOW DO I KNOW IF I HAVE ASTIGMATISM?
While you are waiting to see your optician, you can try the following at home:
What do your results mean?
If you do not have astigmatism, the lines should appear sharply focused and equally dark. You may have astigmatism if some sets of lines appear sharp and dark, while others are blurred and lighter. Whatever your result, an astigmatism diagnosis can only be confirmed by an optician.
Blurry vision may not always be the result of astigmatism, so you must seek an optician’s professional opinion. An optician will carry out a number of tests to understand your prescription.
If you have regular astigmatism don’t worry, it can easily be corrected with glasses or soft toric contact lenses. Toric lenses compensate for the individual differences in the shape of your eye, enabling light to focus correctly on your retina. Toric lenses can also correct short-sightedness and long-sightedness at the same time as correcting astigmatism
CONTACT LENSES FOR ASTIGMATISM
For clear vision with astigmatism, your contact lenses need to stay in place and not rotate or shift out of position even with active lifestyles. ACUVUE® Brand Contact Lenses for astigmatism feature unique Eyelid Stabilised Design – a technology that helps ensure your vision stays stable, crisp and clear as you go about your day.
†Please note professional eye examination and fitting fees may apply. UK residents 18 or over only. One trial per person. Eligibility subject to optician approval. Participating opticians only. See link for full terms and conditions.