Understanding Astigmatism: Types, Symptoms, Causes, and Treatments

Astigmatism is a common eye condition affecting people of all ages. It occurs when the cornea (corneal astigmatism) or lens (lenticular astigmatism) of the eye is misshapen, causing light to be refracted improperly and resulting in blurry or distorted vision. In this article, we will explore the different types of astigmatism, their symptoms, causes, and available astigmatism treatment options.

Understanding Astigmatism: Types, Symptoms, Causes, and Treatments Optometrist
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How Different Types of Astigmatism Affect Your Eyesight

At Specialty Vision, we recommend optometrists that specialize in diagnosing and treating astigmatism, helping patients achieve better vision. There are different types of astigmatism, including regular and irregular astigmatism, each with its own set of symptoms.

Here are the symptoms of each type:

Regular astigmatism

Regular astigmatism occurs when the cornea or lens is curved more in one direction than the other, creating a football-shaped cornea instead of a spherical one. This type of astigmatism is often present at birth, and many people may not even realize they have it until they get an eye exam. The symptoms of regular astigmatism include:

  • Blurred or distorted vision at all distances
  • Difficulty seeing fine details, such as small print or faces from a distance
  • Eyestrain or headaches, especially after reading or using a computer for a long time
  • Squinting or tilting the head to see more clearly

Irregular astigmatism

Irregular astigmatism is less common and occurs when the cornea or lens has an irregular shape, causing light to focus at multiple points on the retina, rather than a single point. This type of astigmatism can be caused by various factors, including eye injuries or surgery, keratoconus, scarring of the cornea, or certain types of contact lenses. The symptoms of irregular astigmatism can be more severe and may include:

  • Distorted or double vision
  • Halos or glare around lights, especially at night
  • Difficulty seeing in low light or in bright sunlight
  • Eyestrain or headaches, especially after reading or using a computer for a long time

It is important to note that the symptoms of astigmatism can be similar to those of other vision problems, such as nearsightedness, farsightedness, and functional vision issues. That's why it is essential to get regular eye exams to detect and treat astigmatism early, to prevent further vision problems. If you are experiencing any of these symptoms, you can reach out to your nearest Specialty Vision practice either via a call or in-person visit. 

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Diagnosing Astigmatism: What to Expect During Your Eye Exam

There are two main types: regular astigmatism and irregular astigmatism. Here are some of the the tests that we may perform during an astigmatism diagnosis:

Regular astigmatism

Visual acuity test

This test measures how well you can see letters or symbols on an eye chart at different distances. If you have astigmatism, your vision may be blurry or distorted in certain directions.

Refraction test

This test determines your exact eyeglass or contact lens prescription by measuring how your eye focuses light. If you have astigmatism, your prescription will include a cylinder power to correct the irregular curvature of the cornea.

Keratometry

This test measures the curvature of the cornea using a specialized instrument called a keratometer. This can help determine the severity and type of astigmatism.

Corneal topography

We may decide to use this test to provide a detailed map of the curvature of the cornea, which can help diagnose and monitor astigmatism.

Irregular astigmatism

Visual acuity test

Like with regular astigmatism, a visual acuity test can reveal blurry or distorted vision in certain directions.

Refraction test

This test can determine the overall prescription needed to correct vision, but may not be able to fully correct irregular astigmatism.

Keratometry

This test can help diagnose irregular astigmatism caused by corneal disorders such as keratoconus.

Corneal topography

This test is especially useful in diagnosing irregular astigmatism, as it can provide a detailed map of the cornea's irregular curvature.

It is important to note that not all cases of astigmatism are the same, and some patients may have both regular and irregular astigmatism. In addition, astigmatism can occur alongside other vision problems such as nearsightedness or farsightedness. Therefore, a comprehensive eye exam is essential for accurately diagnosing and treating astigmatism.

Astigmatism Treatment Options: Find the Best Solution for Your Vision

Astigmatism Treatment Options: Find the Best Solution for Your Vision

There are several treatment options available for astigmatism correction in different types of astigmatism.

Regular astigmatism

Eyeglasses or contact lenses

Prescription eyeglasses or contact lenses can correct the curvature of the cornea, allowing the eye to focus light properly. Toric lenses are specially designed for astigmatism and provide clear vision at all distances.

Refractive surgery

LASIK or other types of refractive surgery can reshape the cornea to correct astigmatism. This procedure can be highly effective and may provide long-term improvement in vision.

Orthokeratology

This non-surgical procedure involves wearing specialized contact lenses at night to reshape the cornea temporarily. This can provide clear vision without the need for eyeglasses or contact lenses during the day.

Irregular astigmatism

Gas permeable contact lenses

These rigid contact lenses can provide clear vision by creating a smooth surface on the cornea. They are often used to correct irregular astigmatism caused by keratoconus or other corneal disorders.

Scleral lenses

These specialized contact lenses are larger than regular contact lenses and rest on the white part of the eye. They can correct irregular astigmatism by creating a new smooth ocular surface over the irregular cornea.

Corneal cross-linking

This procedure involves applying a special solution to the cornea and exposing it to UV light. This can strengthen the cornea and prevent it from becoming more irregular, improving vision and preventing further damage.

Refractive surgery

In some cases, LASIK or other types of refractive surgery can be used to correct irregular astigmatism. However, this is less common than for regular astigmatism, and the success rate may be lower.

It is important to note that not all patients with astigmatism may be candidates for all treatment options. The best treatment option will depend on the severity and type of astigmatism, as well as the patient's overall eye health and lifestyle.

In addition to these treatment options, there are also several lifestyle changes that can help manage astigmatism and improve overall eye health. These include:

  • Taking regular breaks when using the computer or reading to prevent eyestrain
  • Wearing sunglasses or other protective eyewear when outdoors to protect the eyes from UV radiation
  • Eating a healthy diet rich in vitamins and minerals that support eye health, such as leafy greens and omega-3 fatty acids
  • Quitting smoking, which can increase the risk of developing vision problems
Astigmatism Treatment Options: Find the Best Solution for Your Vision

Astigmatism Treatment Options: Find the Best Solution for Your Vision

Here are the different types of lenses used to correct different types of astigmatism:

Toric lenses

These are specially designed soft contact lenses or intraocular lenses (IOLs) that have different powers in different meridians. Toric lenses are used to correct regular astigmatism, which occurs when the cornea or lens is shaped like a football rather than a basketball. Toric lenses are designed to fit the unique curvature of the eye and correct the astigmatism.

Spherical lenses

These are standard lenses used to correct nearsightedness or farsightedness, but they can also correct small amounts of astigmatism. Spherical lenses are not as effective in correcting astigmatism as toric lenses, but they can still provide some improvement in vision.

Rigid gas permeable (RGP) lenses and Scleral lenses

These are hard, gas-permeable lenses that are more effective in correcting astigmatism than spherical lenses. RGP and scleral lenses are designed to maintain their shape on the cornea, which helps to correct irregular astigmatism caused by corneal irregularities, such as keratoconus.

Hybrid lenses

These lenses have a rigid gas-permeable center and a soft lens outer rim, which makes them more comfortable than RGP lenses while still providing the benefits of hard lenses for correcting astigmatism.

Custom wavefront-guided lenses

These are custom-made contact lenses that are designed using advanced technology to map the unique shape of the eye and correct irregular astigmatism. Wavefront-guided lenses provide a more personalized and precise correction than standard lenses.

Common Questions

Astigmatism is classified into five different types based on the orientation of the principal meridians, which are the two meridians with the most and least refractive power and astigmatism causes. The five types of astigmatism are simple myopic astigmatism, compound myopic astigmatism, simple hyperopic astigmatism, compound hyperopic astigmatism, and mixed astigmatism.
The most common type of astigmatism is myopic astigmatism, which occurs when one meridian of the eye is nearsighted, and the other is normal. This accounts for approximately 70-75% of cases of astigmatism.
There is no specific level of astigmatism that is considered "bad" as the severity of astigmatism can vary from person to person. The severity of astigmatism is typically measured in diopters, with a higher number indicating a more severe astigmatism. Our optometrist can determine the severity of your astigmatism and recommend the best course of action for correcting it.
Astigmatism is neither farsighted or nearsighted. Astigmatism is a refractive error that occurs when the cornea or lens of the eye is not evenly curved in all directions, causing light to focus unevenly on the retina.
Whether or not you should wear glasses all the time for astigmatism depends on the severity and type of astigmatism. If your astigmatism is mild, you may not need to wear glasses all the time, and you may only need them for specific activities, such as driving or reading. However, if your astigmatism is severe or accompanied by other refractive errors, such as nearsightedness or farsightedness, you may need to wear glasses all the time to correct your vision. Our optometrist can recommend the best course of action for correcting your astigmatism based on the results of your eye exam.
The most common type of astigmatism is myopic astigmatism, which occurs when one meridian of the eye is nearsighted, and the other is normal. This accounts for approximately 70-75% of cases of astigmatism. Myopic astigmatism can be corrected with glasses, contact lenses, or refractive surgery, depending on the severity and type of astigmatism.
Astigmatism affects how you see by causing the light entering the eye to focus unevenly on the retina. This can cause objects to appear blurry or distorted, especially at a distance. The degree of astigmatism can vary from mild to severe, and the symptoms may depend on the type and severity of the astigmatism. In some cases, astigmatism may be accompanied by other refractive errors, such as nearsightedness or farsightedness, which can further affect vision. Astigmatism can be corrected with glasses, contact lenses, or refractive surgery, depending on the severity and type of astigmatism.
To determine the type and severity of astigmatism, you need to visit our optometrist for a comprehensive eye exam. During the exam, we will measure the shape of your cornea and the power of your lens using special instruments. This will help determine the type and severity of astigmatism, as well as any other refractive errors you may have. Based on the results of the exam, we can recommend the best course of action for correcting your astigmatism.
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Don't Let Astigmatism Blur Your Vision: Book an Eye Exam Today!

If you're experiencing any of the symptoms mentioned above, it's essential to schedule an eye exam with our optometrist to accurately diagnose and treat astigmatism. Whether you have regular or irregular astigmatism, there are several treatment options available, including eyeglasses, contact lenses, refractive surgery, or other procedures. We will work with you to determine the best treatment option based on your individual needs and lifestyle.

Visit a Routine Eye Care optometrist at a Specialty Vision practice near you:
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