Can You Develop Astigmatism? Causes, Symptoms and Treatment

Astigmatism is a refractive error that can make vision blurred or distorted at any distance. It happens when the cornea or the lens inside the eye has a different shape from normal, so incoming light does not focus evenly. Some people are born with astigmatism, while others develop it during childhood or young adulthood; it can also appear after an eye injury or eye surgery.

Key Points

• Astigmatism can be present from birth or develop later.
• Symptoms may include blurred vision, squinting, headaches, eye strain and difficulty seeing at night.
• An eye examination is needed to diagnose and measure it.
• Glasses and contact lenses are common corrections; surgery is suitable only for selected patients.
• Astigmatism cannot generally be prevented, but eye protection can reduce avoidable injury.

What Astigmatism Means

In an eye without significant astigmatism, the cornea and lens focus light onto the retina in a regular way. With astigmatism, differences in curvature cause a refractive error. Astigmatism may occur alone or together with short-sightedness or long-sightedness. Our separate guide explains what astigmatism means in more detail.

Can Astigmatism Develop Later in Life?

Yes. The National Eye Institute states that many people develop astigmatism as children or young adults, and that it may also develop after an eye injury or surgery. A change in prescription does not by itself reveal the cause, so new or worsening blur should be assessed rather than self-diagnosed.

Reading in dim light, sitting close to a screen or using digital devices can cause temporary discomfort or eye strain, but these habits are not established causes of astigmatism. Astigmatism itself is not generally preventable.

Symptoms and Diagnosis

Possible symptoms include blurred or distorted vision, squinting, headaches, eye strain and difficulty seeing at night. Mild astigmatism may cause no obvious symptoms. Children may not recognise that their vision is unclear, which is one reason routine vision checks matter.

An optometrist or ophthalmologist can check visual acuity and refraction and examine the eyes. Depending on the clinical question, measurements of corneal curvature or corneal topography may be used. These tests should be interpreted as part of a complete assessment.

Treatment and Correction

Mild astigmatism may not require correction. When correction is needed, prescription glasses or contact lenses are the usual options. The appropriate prescription and lens type depend on the measurements, eye health, comfort and daily needs of the individual.

Laser refractive procedures can reshape the cornea and may be considered for selected adults after a detailed examination. They are not suitable for everyone and can cause side effects or complications. Read how LASIK eye surgery works, then discuss candidacy, alternatives and realistic outcomes with a qualified eye surgeon.

A toric intraocular lens may be considered for selected patients who need lens surgery, including some people having cataract surgery. It is not a routine first-line treatment for an otherwise healthy eye. Our guide to trifocal and toric intraocular lenses outlines the distinction.

When to Arrange an Eye Examination

Arrange an eye examination if blur, headaches, squinting, night-vision difficulty or eye strain persists, or if an existing prescription no longer gives clear vision. Seek urgent medical assessment for sudden loss or marked change of vision, severe eye pain, a new curtain or shadow, or flashes and a sudden increase in floaters; these are not symptoms to attribute to routine astigmatism without assessment.

Independent Patient Information

• National Eye Institute: Astigmatism
• National Eye Institute: Surgery for refractive errors
• NHS: Astigmatism

Frequently Asked Questions

Can you suddenly develop astigmatism?

Astigmatism can develop or change, including after injury or surgery. A sudden change in vision needs an eye assessment because other conditions can produce similar symptoms.

Can screens cause astigmatism?

Screen use can contribute to temporary eye strain or dryness, but it is not an established cause of astigmatism.

Can astigmatism be prevented?

There is no established way to prevent astigmatism in general. Protective eyewear can reduce the risk of injuries that may affect the cornea.

Does everyone with astigmatism need surgery?

No. Many people use glasses or contact lenses, and mild astigmatism may not need correction. Surgery requires individual assessment and informed consent.