Astigmatism is a common refractive error caused by an irregular curvature of the cornea or lens. Instead of a perfectly round surface, it’s more football-shaped, which bends light unevenly and leads to blurred or distorted vision.

Is “stigmatism” or “a stigmatism” the same thing as astigmatism?

Yes—people often say “stigmatism” or “a stigmatism,” but the correct term is astigmatism. The condition and meaning are the same; the difference is only the wording.

How is astigmatism treated?

Astigmatism is typically corrected with prescription glasses or toric contact lenses. Some people may be candidates for refractive surgery such as LASIK or PRK. An eye exam can determine the best option for you.

What is Astigmatism?

Last updated: February 14, 2026

Astigmatism is a common refractive error that occurs when the cornea or lens of the eye has an irregular shape. What is astigmatism, exactly? Instead of being perfectly round, the cornea is shaped more like a football, leading to blurred or distorted vision. This irregular curvature affects how light enters the eye, preventing it from focusing correctly on the retina.

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This makes everyday tasks like reading, driving, or using a computer more challenging without proper correction. Because of its prevalence, many people don’t even realize they have astigmatism until an eye exam reveals it.

Note: Some people mistakenly call this condition “stigmatism” or say “a stigmatism.”
The correct term is astigmatism – learn why in our full guide: Astigmatism vs Stigmatism.

Symptoms

Many people with astigmatism experience:

Blurry or distorted vision at any distance
Eye strain or discomfort
Headaches after prolonged visual tasks
Difficulty seeing at night
Squinting to see objects more clearly

Since these symptoms can also be linked to other vision problems, an eye exam is necessary to determine the cause.

In many cases, the most practical next step is proper correction. Learn the benefits of prescription glasses, especially when distortion makes focusing feel constant and tiring.

Causes of Astigmatism

This condition can be:

Hereditary – It often runs in families and may be present at birth.
Developed over time – Changes in the shape of the cornea can occur due to aging, eye surgery, or eye injuries.
Associated with other vision conditions – Many people with nearsightedness (myopia) or farsightedness (hyperopia) also have astigmatism.

How is it Diagnosed?

An optometrist or ophthalmologist can diagnose this condition through a comprehensive eye exam, including tests to measure the cornea’s curvature and how light focuses inside the eye.

Treatment Options

Fortunately, this condition is treatable with:

Prescription Glasses – Special lenses help compensate for the cornea’s irregular shape.
Contact Lenses – Toric lenses are designed to correct it.
Refractive Surgery – Procedures like LASIK or PRK reshape the cornea to improve vision.

If you’re experiencing blurry or strained vision, a simple eye exam can determine the cause. Proper correction can significantly improve clarity and comfort in daily activities. For a more in depth look, please visit our post about Astigmatism Vision Distortions.

Wondering how astigmatism differs from “stigmatism”? See our full comparison: Astigmatism vs Stigmatism

For more information about eye health and what is astigmatism, visit the American Academy of Ophthalmology’s Eye Health A-Z.

This content is for informational purposes only and is not a substitute for professional medical advice. Consult an eye care professional for concerns about your vision.

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