Astigmatism Disease

Astigmatism Cause & Description

View Video

What is Astigmatism?

Astigmatism is a common vision condition caused by an irregular curve of the cornea or lens. Instead of being round like a basketball, the surface of the eye is shaped more like a football. This uneven curve prevents light from focusing clearly, leading to blurry or distorted vision at any distance.

Astigmatism can occur in one eye or both. Many people notice difficulty reading, headaches, tired eyes, or poor night vision, which are typical astigmatism symptoms.

Types of Astigmatism

There are several types of astigmatism, including:

Corneal astigmatism – Occurs when the cornea has an uneven curve. This is the most common type and is often responsible for blurred or distorted vision.
Lenticular astigmatism – Caused by an irregularly shaped lens inside the eye. The lens bends light unevenly, creating similar symptoms to corneal astigmatism.
With-the-rule astigmatism – The eye curves more steeply vertically than horizontally. This is frequently seen in younger individuals.
Against-the-rule astigmatism – The eye curves more steeply horizontally than vertically, often becoming more common with age.
Oblique astigmatism – The steepest and flattest curves lie at diagonal angles rather than horizontal or vertical positions.

Astigmatism Causes

There are several known causes of astigmatism. The most common is genetics.

Astigmatism develops when the eye’s focusing surface is not perfectly round. Most people are simply born with this shape, which is why astigmatism often appears early in life. The cornea may curve more steeply in one direction than the other, creating uneven focus and blurred vision.

Changes can also occur later in life. Certain eye conditions that alter the cornea's structure, prior eye injuries, or age-related changes within the eye may contribute. While the degree of astigmatism varies from person to person, the underlying cause is always the same: an uneven surface that bends light.

Astigmatism Symptoms

Astigmatism can affect vision in subtle or noticeable ways. Here are some symptoms:

Blurred or distorted vision at any distance
Frequent squinting to see objects more clearly
Headaches after reading or screen use
Eye strain or a feeling of tired eyes
Difficulty seeing clearly at night or in low light
Uneven or double vision when one eye is more affected
Trouble focusing for long periods, especially during close work

Astigmatism in one eye symptoms include uneven blur or a feeling that the eyes do not work together comfortably.

What Causes Astigmatism to Worsen?

Astigmatism can slowly worsen as the eye changes with age, from frequent eye rubbing, or from unmanaged corneal disorders. Some individuals develop lenticular astigmatism, which occurs when the lens inside the eye is irregular rather than the cornea.

How Is Astigmatism Diagnosed?

An astigmatism test is quick and painless. Your eye specialist will:

Measure the curvature of your cornea
Assess your prescription
Examine the overall health of your eye

These tests help determine whether your astigmatism is mild, moderate, or severe.

How to Cure Astigmatism Permanently

Glasses and contact lenses correct vision but do not change the eye’s shape. Permanent solutions may include:

Laser Surgery for Astigmatism

Laser procedures such as LASIK or PRK reshape the cornea to improve focus. These treatments offer long-term results for suitable candidates.

Other options include:

Toric contact lenses
Corneal cross-linking for keratoconus
Refractive lens surgery for advanced lenticular astigmatism

Glasses for Astigmatism

Glasses for astigmatism contain a specific cylinder correction to balance how light enters the eye. For many people, this is the simplest and most effective way to enjoy clear and comfortable vision.

Frequently Asked Questions

Is astigmatism genetic?

Yes. It commonly runs in families.

Is astigmatism normal?

Very. It is one of the most common eye conditions worldwide.

What diseases cause astigmatism?

Keratoconus, corneal scarring, inflammation, and severe dry eye can change the eye’s shape and worsen astigmatism.

Can astigmatism cause blindness?

Astigmatism alone does not cause blindness. However, severe corneal diseases that alter the cornea's structure can lead to significant vision problems if not treated early. Proper astigmatism treatment helps protect your long-term vision.

What is lenticular astigmatism?

It is astigmatism caused by an uneven lens inside the eye rather than by the cornea.

What are the best glasses for astigmatism?

Glasses with cylinder correction designed to match your exact prescription.

What astigmatism treatment options are available?

Glasses, toric contact lenses, laser surgery, corneal cross-linking, and lens replacement surgery.