Astigmatism

Astigmatism is a refractive error similar to being long or short sighted; it's a problem with how the eyes focus light. It is not a disease of the eyes. When light enters the eyes, it should enter as a single focal ray of light. With astigmatism there are multiple focal rays of lights, it’s our job as an optician to bring it back to one using glasses or contact lenses. Most people have some degree of astigmatism, All the opticians here at eyedeal vision have astigmatism.

Blurred vision

Eye strain

Headaches

Visual difficulty and/or discomfort in prolonged tasks such as reading

Screwing your eyes to see better (squinting your eyes)

Astigmatism is when the cornea (which is the clear layer that covers the iris) is irregular in shape. Instead of being a symmetrical round surface like a football, it is more like a rugby ball.

Astigmatism can also be caused by the shape of the lens inside the eye being more like a rugby ball or oval. This is called lenticular astigmatism.

There are different types of astigmatism, these are:

• Myopic astigmatism – short sighted astigmatism

• Hyperopic astigmatism – long sighted astigmatism

• Mixed astigmatism

Astigmatism is also classified as regular or irregular.

1. Regular astigmatism is when the cornea is curved more in one direction than the other, rugby ball shaped. It can be corrected easily with glasses or astigmatism contact lenses.

2. Irregular astigmatism is less common and happens when the surface curve of the cornea isn't even. It may be the result of an eye injury, surgery or an eye condition, such as keratoconus.

Astigmatism is usually detected when you attend your annual eye test. We will also be able to detect if you are long or short sighted too.

Astigmatism Correction or treatment

Astigmatism, like short or long sightedness can be corrected using glasses, contact lenses or refractive laser surgery.

Glasses; we will test your eyes to see what prescription you need. We will use spherical lens powers to correct for long or short sightedness and cylinder lens powers to correct astigmatism. The cylinder power always lies on an axis between 0 to 180 degrees. These measurements will give the prescription you require for your glasses. For example an astigmatic prescription may look something like this:

sphere/cylinder x axis  

-1.00/-1.00 x 180

Contact lenses are available in soft, hybrid or hard. We generally use soft toric contact lenses to correct most patients with astigmatism. You will need a current eye test prescription to assess which manufacturer's contact lens type will be best suited to you. Again your prescription will likely include sphere/cylinder x axis.

Hybrid and hard (gas permeable) contact lenses are very useful for anyone that has a complicated prescription or has an eye condition where their vision cannot be corrected using a traditional soft toric lens.

Please note a contact lens fit or contact lens check is completely different to an eye test. They are separate tests; a contact lens test entails different assessments of the eye compared to your eye test.

Refractive laser surgery such as LASIK can be used to correct most types of astigmatism. Please feel free to ask us for advice if you are thinking about laser surgery.

We advise that you have an annual eye test to check the health of your eyes and ensure you are wearing the most up to date prescription.