What is Astigmatism?

It is very common for people to have an astigmatism which occurs when the eye is not perfectly circular and can cause blurry vision if it hasn’t been properly corrected.

What is Astigmatism? in Olympia

Not all eyes are perfect circles, sometimes they are more oval shaped. If a person has an irregular shape or curvature of the cornea (the clear part that covers the surface of the eye) or lens inside the eye then it results in an astigmatism which is quite common. In a round eye, or in an eye without astigmatism, the cornea and lens allow the light to focus at a single point on the retina. If there is an astigmatism, then the cornea or lens is more elliptical which causes the light either to focus before or after the retina. It is common to have astigmatism along with other vision conditions such as nearsightedness or farsightedness. Together, these vision conditions are called ‘refractive errors’ because they affect how the eyes bend or ‘refract’ incoming light. People with astigmatism tend to require a more specific prescription for glasses or contact lenses which allows light to bend properly on the shape of their eye. There is an added component of a prescription for glasses or contact lenses called the cylinder, which is customized to correct an astigmatism.

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Some people don’t notice any symptoms while others who have astigmatism could experience any of the following:

  • Blurry or distorted vision
  • Eye strain/ irritation
  • Headaches
  • Squinting 

These symptoms are not necessarily caused by astigmatism, as they could be caused by other health or vision conditions. If you are experiencing any of these symptoms, please schedule an appointment with your eye doctor. You will have a comprehensive eye exam in which a proper diagnosis will be provided.

Causes of Astigmatism

Astigmatism is generally a condition people are born with and is inherited. It can also be developed due to an eye disease, injury or surgery. Astigmatism can be caused by a degenerative eye disorder called keratoconus which is when the cornea (the clear part that covers the surface of the eye) becomes thinner and more cone-shaped.

There are two types of astigmatism, each with their own cause due to the anatomy of the eye:

  1. Corneal astigmatism - this is the most common type and it’s a result of an irregularly shaped cornea. The cornea is a clear layer which covers the surface of the eye and contributes greatly to the way we see.
  2. Lenticular astigmatism - this type is caused by an irregular lens inside of the eye. 
Causes of Astigmatism
Risk Factors

Risk Factors

Astigmatism can occur in people of all ages from children to adults. People with the following conditions may be more prone to develop astigmatism:

  • Family history of astigmatism
  • Family history of keratoconus or other corneal conditions
  • Excessive nearsightedness or farsightedness as these could affect the shape of your eye

Common Questions

No, this is a myth. One cannot develop astigmatism because they read in low light settings or because they sit close to the TV. Astigmatism is most often an inherited condition that people are born with.
Due to the fact that astigmatism is connected to the anatomy and shape of the eye, it is most often an inherited condition and it cannot be prevented. However, there are wonderful optical corrections for astigmatism. In the prescription for glasses or contact lenses, there will be an added component called a cylinder which corrects the astigmatism. There is also the option of refractive surgery which is used to correct the astigmatism in the eye, similar to how laser eye surgery corrects nearsightedness or farsightedness.
What is Astigmatism?
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When to See the Eye Doctor

If you are experiencing unclear vision or any symptoms of astigmatism, such as headaches, eye strain or irritation please schedule an eye exam. Your eye doctor will be able to diagnose an astigmatism or the relevant cause for these symptoms and will provide the proper treatment. Children and many adults will not notice symptoms of astigmatism so it’s very important to go for routine eye exams from a young age so that any vision or eye conditions can be detected and corrected early on.

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400 Yauger Way SW. Bldg 1, Ste A Olympia, WA 98502
(360) 459-1097
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