types of astigmatism

Astigmatism is a very common vision problem, but most people don’t really understand what it is. Although the name may sound a bit overwhelming, the fact is that astigmatism is just a refractive error. This means that it is a problem with the way your eyes focus light. When you have astigmatism, light does not gather into a single focus on your retina. Instead, it scatters into multiple focal points. The result is a lack of clear vision.

How Can You Tell If You Have Astigmatism?

If you tend to squint a lot, you may have astigmatism. Additionally, people who have astigmatism experience distorted or blurry vision both up close and in the distance. If you allow astigmatism to go uncorrected for an extended period of time, you may experience headaches and eye strain. This is especially true when you are reading or performing some other task that requires good vision.

What Is The Cause Of Astigmatism?

Think of your eyeball as being divided into four quadrants. These are called meridians. When you have astigmatism, the cornea of your eye is irregularly shaped because it is spherical rather than round.

This asymmetry can result in having the meridians oddly curved, and this unevenness can cause refractive problems. The type of astigmatism that results from this is called corneal astigmatism.

Another problem that sometimes occurs is that the lens of your eye may be oddly shaped. This can cause astigmatism. This type of astigmatism is called lenticular.

Sometimes Astigmatism Combines With Other Vision Problems

Types of Astigmatism

1. Myopia with astigmatism: With this type of astigmatism, one or both of the principal eye meridians (the ones that are the flattest and the steepest) are nearsighted. In the event that both of the principal meridians are nearsighted, they will be myopic in varying degrees.
2. Hyperopia with astigmatism: Hyperopia is farsightedness. With this type of astigmatism, one or both of the principal meridians will be farsighted. If they are both farsighted, they will be so to differing degrees.
3. Mixed astigmatism: If one principal meridian is farsighted and the other one is nearsighted, you have mixed astigmatism.

More Variances in Astigmatism

In addition to the variations of corneal and lenticular astigmatism; myopic, hyperopic and mixed astigmatism, there are also variations in classification which are termed as “regular” or “irregular”.

With regular astigmatism, the principal meridians will be perpendicular to one another. With irregular astigmatism, this will not be the case. For the most part, cases of astigmatism are corneal and fall into the regular category.

Cases of irregular astigmatism are usually the result of an injury to the eye that causes corneal scars. This type of astigmatism can also occur in people who have had eye surgery or who have experienced a disease known as keratoconus. This condition causes the cornea is thin gradually.

It’s Complicated!

It’s easy to see that there’s quite a bit to keep in mind when diagnosing and treating astigmatism. Luckily, as a patient a main thing you need to keep in mind is that if you are experiencing blurred vision, headaches, squinting or any other symptom of farsightedness (hyperopia), nearsightedness (myopia) or other vision problems the only thing you need to do is see your optometrist for testing and vision correction. Don’t take chances with your vision, see your optometrist on a regular basis.