Can Glasses Fix Astigmatism?

Author: Anna Barden

Astigmatism and Its Impact on Vision

Astigmatism is a refractive error in which the cornea or lens of the eye is irregularly curved. Typically, the cornea of an eye with astigmatism has an uneven curvature, more like a football, while the curvature of a normal cornea has an overall round shape, more like a basketball.

Other refractive errors include nearsightedness and farsightedness. Nearsightedness makes it difficult to see things far away and farsightedness typically makes it difficult to see things close up. But astigmatism can make things blurry or distorted from any distance.

You can get toric contact lenses or glasses for astigmatism to correct the blurriness or distortion caused by astigmatism. It’s best to discuss your options with your eye care provider at your next exam.

How Does Astigmatism Affect Vision?

To understand how astigmatism affects vision, it’s important to review other common refractive errors and why they occur. In a regular-shaped eye, light enters the clear, front part of your eye and is focused directly on the retina (the light-sensitive tissue at the back of the eye). This produces a clear image.

When light is focused too far in front of the retina, it results in myopia (nearsightedness), causing blurry vision at a distance. When light is focused too far behind the retina, it leads to hyperopia (farsightedness), affecting near vision. Both conditions are refractive errors that cause blurry vision at specific distances.

In an eye with astigmatism, light does not focus properly on the retina because the irregularly shaped cornea or lens causes light rays to scatter, causing blurry vision at all distances. Other symptoms such as headaches, eye strain or discomfort, squinting to see clearly, or distorted vision can occur if you have astigmatism.

Some people have both astigmatism and nearsightedness or farsightedness. Contacts or eyeglasses can correct these refractive errors.

How Glasses Can Correct Astigmatism

Your prescription for astigmatism correction glasses is designed to refocus light so that it lands directly on the retina and provides you with clear vision.

Do you need glasses for astigmatism? If you have mild astigmatism and don’t experience blurry vision or other symptoms, glasses may not be necessary. Your eye doctor will let you know whether or not you need astigmatism spectacles at the time of your eye exam.

Besides astigmatism glasses, you can correct your vision with special contact lenses. Soft toric lenses are generally more common, especially for moderate astigmatism. Rigid gas permeable (RGP) lenses may be selected for their superior visual acuity, particularly in cases of severe astigmatism. Refractive surgery may also be an option for those who don’t want to wear contacts or glasses for astigmatism. Talk to your eye doctor about the best option for you.

What Level of Astigmatism Requires Glasses?

Astigmatism is measured in units called diopters (D). It ranges from mild to severe or extreme as follows:

• Mild astigmatism – 1.00 D or less.
• Moderate – 1.00 to 2.00 D.
• Severe – 2.00 to 4.00 D.
• Extreme – 4.00 D or more.

The level of astigmatism that requires glasses or contacts to see clearly starts in the moderate range at about 1.50 D or more.

People with lower degrees of astigmatism (around 0.50 D to 0.75 D) may not need glasses or contacts. Your eye doctor will determine whether or not you need spectacles.

Choosing the Best Astigmatism Glasses for You

The right astigmatism glasses are made based on your vision prescription. But your doctor may recommend certain lens materials depending on your level of astigmatism, your overall prescription, and other factors.

Best Glasses Lenses for Astigmatism

The amount of astigmatism you have may be more well-suited by one lens material than another. If you have a strong prescription, you may want to consider a higher-index lens, which is thinner and lighter. Here are some types of lenses to choose from for your astigmatism eyeglasses:

• CR-39 (standard plastic) — This is a lightweight standard lens that tends to be thicker than others. Best for mild astigmatism (1.00 D or less).
• Polycarbonate — This is a more impact-resistant lens, ideal for those with more active lifestyles. Best for moderate to severe levels of astigmatism (1.00 to 4.00 D).
• Trivex — These are lightweight, supreme-quality lenses that are made of a urethane-based pre-polymer material. Best for moderate to severe levels of astigmatism (1.00 to 4.00 D).
• High-index — These are lightweight and thin lenses that have a higher index of refraction. Best for severe and extreme levels of astigmatism (2.00 to 4.00 D or more).

Reading Glasses for Astigmatism

Over-the-counter reading glasses don’t correct astigmatism. This type of refractive error requires prescription eyeglasses or contacts for proper correction. Talk to your eye care provider about your options if you need both a reading prescription and astigmatism correction.

Tips for Adjusting to New Glasses for Astigmatism

How long does it take for glasses to correct astigmatism? Your prescription lenses will provide clear vision as soon as you put them on. But it may take time for you to get used to the change. Some people adjust to new glasses in as little as a few hours, while others may need as much as two weeks.

Wearing glasses for astigmatism for the first time may cause symptoms such as distorted vision, changes in depth perception, and more. You may also experience headaches, eye strain, or dizziness. But there are a few things you can do to help the process.

• Ensure your frames fit properly. An improper fit can cause you to misfocus your vision, and it can also be uncomfortable.
• Wear your new glasses as often as you can. You’ll adjust more quickly the more you wear your glasses.
• Don’t switch back to your old glasses. This can make the adjustment period even longer for your new prescription.
• Clean your lenses regularly. Dirty glasses can be distracting and make it harder for you to focus.

Seeing clearly is crucial for everyday life. Don’t hesitate to contact your doctor if you have any questions or concerns about your new astigmatism glasses. And don’t forget to stay up to date on your routine eye exams!