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What Causes Astigmatism to Worsen?

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A close up of an eye with astigmatism.

Astigmatism is a refractive error that affects the eye’s ability to focus light. Astigmatism causes blurry vision due to an irregularly shaped cornea or lens in the eye. 

While many people live with astigmatism without experiencing a significant change in their condition, some may notice a worsening of symptoms if left untreated, with age, and if accompanied by other eye conditions. 

Your eye doctor can diagnose astigmatism with an eye exam and determine whether you need corrective lenses to help you see clearly. 

What Is Astigmatism?

Astigmatism is an eye condition or refractive error resulting from an irregularly shaped cornea (the clear front part of the eye) or lens (located behind the iris that helps the eye focus). In a healthy eye, the cornea and lens are round, allowing light to pass through and focus on the retina (the light-sensitive tissue at the back of the eye) to form clear images. 

However, in astigmatism, the cornea or lens is oval or irregular, causing light to scatter and not focus on the retina, resulting in blurry vision at all distances. You can have astigmatism with other refractive errors, such as myopia (nearsightedness) and hyperopia (farsightedness). Some people are born with astigmatism, but children and young adults can also develop astigmatism. 

Symptoms of Astigmatism

You may not have noticeable symptoms with mild astigmatism, which makes eye exams important for detecting this refractive error early, especially in children who may not realize they have a vision problem. Common symptoms of astigmatism can include:

  • Blurry or distorted vision
  • Squinting to see clearly
  • Headaches
  • Eye strain
  • Trouble seeing at night

Causes of Worsening Astigmatism

Astigmatism can worsen over time. Progressing astigmatism can have several causes. 

Genetic Predisposition

Anyone can get a refractive error. But, one of the primary factors influencing the progression of astigmatism is genetic predisposition. Individuals with family members wearing glasses or contact lenses or a history of astigmatism are more likely to develop the condition. Genetic factors play a crucial role in determining cornea and lens shape and structure, contributing to the development and exacerbation of astigmatism over time.

Age-Related Changes

As we age, various physiological changes occur in the eye that can impact the progression of astigmatism. The lens, responsible for focusing light onto the retina, gradually loses its flexibility and elasticity with age. This natural aging process can lead to astigmatism worsening over time. Additionally, alterations in the corneal shape due to aging can contribute to the progression of astigmatism in some individuals.

Unmanaged Refractive Errors

Failure to address and correct astigmatism can contribute to its progression. Uncorrected refractive errors can further strain the eye, leading to changes in corneal shape over time. Specialty contacts for patients with astigmatism can gently reshape the cornea and provide clear vision. 

Laser eye surgery can correct astigmatism by reshaping the cornea to alter how light enters the eye. However, not everyone is a candidate for laser eye surgery. Speak to your eye doctor to find out if you’re a candidate. 


While not directly causing astigmatism, keratoconus can cause worsening of astigmatism. Keratoconus is a corneal disorder that gradually thins and bulges outward, resulting in distorted vision.

Keratoconus can coexist with astigmatism and contribute to its progression, leading to irregular astigmatism or astigmatism that you can not correct with glasses. Managing keratoconus through appropriate interventions, such as specialized contact lenses or surgical procedures, is essential to prevent the worsening of astigmatism.

Chronic eye rubbing is a habit that can cause keratoconus and exacerbate astigmatism. Vigorous eye rubbing, especially over an extended period, can contribute to irregularities in the corneal curvature or changing the corneal shape from cylindrical to cone-shaped, resulting in reduced visual acuity.

Other Causes of Worsening Astigmatism

Trauma or injuries to the eye can cause a change in the shape of the cornea or lens, resulting in or worsening astigmatism. Certain eye surgeries, such as cataract surgery or corneal transplant, can cause astigmatism to worsen. Wearing glasses with an incorrect astigmatism prescription can also worsen symptoms such as blurry vision, eye strain, and headaches. 

A woman smiling while at an eye exam getting glasses fitted.

Early Diagnosis & Treatment for Astigmatism

You may not need prescription eyeglasses for mild astigmatism. However, if you experience eye strain or headaches, speak to your eye doctor about vision correction. The following treatments can correct almost all levels of regular astigmatism:

  • Properly fitted prescription eyeglasses
  • Contact lenses
  • Laser and other refractive surgery
  • Orthokeratology or corneal refractive therapy

Astigmatism is a common eye condition that affects many people and can worsen due to age-related changes, having other eye conditions, and if left untreated. 

Regular eye examinations, early diagnosis and correction of refractive errors, and healthy eye care habits play pivotal roles in maintaining eye health. If you experience any symptoms of astigmatism, book an appointment with Prairie Vision for an eye examination and treatment to prevent your astigmatism from worsening.

Written by Dr. Tanya Jones-Greenwood

Dr. Tanya Jones-Greenwood grew up on her family farm south of Czar and has been a patient with Prairie Vision since she was a child. After receiving her Bachelor of Science Degree from the University of Alberta in 2006 and her Optometry Doctorate from Indiana University in 2010, she returned home.

“I love our local communities and the small-town atmosphere; I couldn’t think of a better place to work and start a family.”

In 2012 she began partial ownership of the office, and in 2014 she became sole owner.

“This is where I grew up. I love caring for the people in my community and want to see us bring big-city technology and skills to our office yet keep the warm and friendly atmosphere.”

Dr. Jones-Greenwood has a special interest in working with children and within the area of vision therapy. She has attended many additional courses listed below. She is a member of the Canadian Optometrists in Vision Therapy and Rehabilitation, the College of Optometrists in Vision Development and the Optometric Extension Program Foundation.

Outside of the office, she enjoys raising her 4 children with her husband and catching up with family and friends. Dr. Jones-Greenwood’s favourite eyewear line is Paradox and Etnia Barcelona.

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