Why does astigmatism change

It occurs when the cornea — the clear front cover of the eye — is irregularly shaped, or sometimes, because of the curvature of the lens inside the eye. When it comes to an eye condition such as astigmatism, it is best to get an astigmatism correction as soon as possible. However, in many cases, individuals fear that they will be injured even further in the surgery and that wearing glasses is a better option. The first reason why you should absolutely get the astigmatism correction surgery is because, in most cases, this surgery takes the form of a LASIK surgery.

If the axis has changed by more than 90 degrees, you may wish to clarify this with our eye doctor, as a variation this large is quite unusual. There are some other factors that could influence a change in the level and angle of astigmatism. These include:. Although most astigmatism changes happen over a period of years, it is not unheard of for them to occur over a much shorter time span. If there are any underlying issues causing your astigmatism measurements to change significantly, they should be detected at this stage.

If you would like more information about astigmatism, or you have been diagnosed and are concerned about how your prescription has changed, our dedicated and knowledgeable team would be happy to advise you. Farsightedness is the opposite — the curvatures are symmetrical but not quite round enough, or the eye is too short from front to back.

Light rays that enter the eye end up at a focal point somewhere behind the retina. With astigmatism, the curvatures are asymmetrical. They are shaped like the side of an American football rather than round like a baseball. This creates multiple focal points of light within the eye, rather than just one. Astigmatism usually occurs along with myopia or hyperopia. The main symptom of astigmatism is blurry or distorted vision at more than one distance. For example, you might need to squint to see the television and the computer screen.

If you notice these issues in yourself or your child, you should schedule an eye exam to find out whether astigmatism is the problem. Read more about the symptoms of astigmatism. Some types of astigmatism probably do have a genetic component. Some evidence also suggests that astigmatism is slightly more common in people of Hispanic and African American descent.

There is also some evidence that smoking during pregnancy can increase the chances of the baby having astigmatism. Most people with astigmatism are born with the condition, but it might not be diagnosed until later.

It can develop at any age, though, from an injury, other eye conditions, after a surgery or due to other changes in the shape of the cornea.

As part of a comprehensive eye exam, your eye doctor can diagnose astigmatism by measuring the curvatures of your corneas and performing tests to see how your eyes refract light onto your retinas. If you have astigmatism, the numbers on your prescription will indicate how much lens power you need to correct for the astigmatism, as well as where the power is needed. This is because the lens will only have corrective curve in one direction, like a cylinder, to balance the powers of the principal meridians of your eye.

The higher the number, the more lens power is needed. It is perpendicular at a degree angle to the corrective meridian. The meridians are numbered in degrees, with the horizontal and vertical meridians at degrees and 90 degrees, respectively. See a helpful graph about meridians and learn more about eyeglass lens prescriptions. However, it will depend on the severity and type of astigmatism.

Also, some types of astigmatism may not be corrected with lenses but can be corrected with refractive surgery. Read more about astigmatism treatments. We recommend them every year for adults and children over age 6 to mitigate any vision issues or other eye health problems. Have questions about astigmatism? Contact your nearest optical store today to speak with an optometrist. To keep tabs on your astigmatism symptoms and prescription, we recommend having regular eye doctor appointments.

Your optometrist will investigate any signs of progression to ensure you get the right treatment when you need it. At first, your astigmatism might be minor, but over time, it can develop. There are many things to consider regarding what causes astigmatism to worsen.

Sometimes, astigmatism can get worse over time for no apparent reason. Other times, it may feel like your astigmatism is worse when you might have another eye issue.

For instance, keratoconus , an uncommon eye condition caused by a narrow, pyramid-shaped cornea, can contribute to severe astigmatism. In some instances, the cornea can expand, which can make it even harder to see.

It can also cause abrupt changes in your eyesight.