Astigmatism Explained Clearly: Understanding the Causes, Symptoms, and Effective Treatments

Do far-away things come into focus for you when you squint? If so, you probably have an astigmatism. Astigmatism, a common vision problem that affects millions worldwide, can be a nuisance in our everyday lives. But, what if we told you that understanding and managing this condition is easier than you think? Let’s get into the topic of astigmatism, and clearly explore its causes, symptoms, and treatment options.

A person removing glasses and everything looks fuzzy

Understanding Astigmatism: A Comprehensive Overview

The severity of astigmatism can fluctuate over time, and some individuals may experience severe astigmatism, which can significantly impact their daily activities and vision. With this in mind, it is a good idea to schedule an appointment with an eye doctor promptly upon noticing any changes in vision or clarity. A comprehensive eye exam can help diagnose astigmatism and other eye conditions in a timely manner, ensuring the best course of action for treatment. And hey, better vision can be enjoyed daily, right?. It is an impactful way to improve quality of life.

The severity of astigmatism can fluctuate over time, and some individuals may experience severe astigmatism, which can significantly impact their daily activities and vision. With this in mind, it is a good idea to schedule an appointment with an eye doctor promptly upon noticing any changes in vision or clarity. A comprehensive eye exam can help diagnose astigmatism and other eye conditions in a timely manner, ensuring the best course of action for treatment. And hey, better vision can be enjoyed daily, right?. It is an impactful way to improve quality of life.

The Role of Cornea and Lens in Astigmatism

The cornea serves as the eye’s outermost lens, regulating and directing the influx of light into the eye, while the lens collaborates with the cornea to appropriately focus light rays onto the retina. The retina is a light-sensitive layer of tissue located at the rear of the eye. The shape of the cornea and lens plays a crucial role in the focusing of light rays on the retina, with a smooth and dome-like shape allowing them to appropriately bend and focus incoming light rays onto the retina. Conversely, if the shape of the cornea or lens is distorted or irregular, it can cause the light to be scattered or not properly focused, resulting in blurred vision.

Astigmatism is a result of an imperfection in the curvature of the eye, particularly in the cornea or lens, which leads to blurred vision at all distances. This irregularity in the shape of the cornea and lens is paramount for vision, as it assists in focusing light onto the retina situated at the back of the eye. If the shape of the cornea or lens is not regular, the light may be dispersed, thereby causing blurry vision.

Diagram of normal eye vs eye with astigmatism

Types of Astigmatism: Corneal and Lenticular

There are two classifications of astigmatism: corneal, impacting the cornea, and lenticular, affecting the lens. Corneal astigmatism is a condition in which the curvature of the cornea is mismatched, causing the eye to focus light unevenly on the retina. On the other hand, lenticular astigmatism occurs when the curves of the lens are mismatched, leading to similar focusing issues.

The difference between corneal and lenticular astigmatism is rooted in the area of the eye affected. Corneal astigmatism is the consequence of an irregular curvature of the cornea, whereas lenticular astigmatism is the effect of an irregular shape of the lens in the eye. Both forms of astigmatism result in blurry vision, making it crucial to identify the specific type for proper treatment.

Regular vs. Irregular Astigmatism

Regular astigmatism has a consistent curvature, whereas irregular astigmatism has an irregular curvature, making it more challenging to correct. With-the-rule astigmatism, commonly observed in younger individuals, is characterized by a corneal shape akin to a football lying on the ground, with the steepest curves running vertically. In contrast, against-the-rule astigmatism, more prevalent among older adults, resembles a football on a tee with the steepest curves running horizontally.

Regular astigmatism can be corrected using glasses, contact lenses, or laser surgery. These methods are highly efficient and precise. However, irregular astigmatism, with its uneven curvature, often necessitates more specialized treatment options, such as custom-designed contact lenses or advanced surgical procedures, to achieve optimal vision correction.

Identifying Astigmatism Symptoms and Causes

Blurred vision, eye fatigue, and headaches are common indicators of astigmatism. The usual causes of astigmatism are generally attributed to:

A person with blurry vision due to astigmatism
  • an abnormal shape of the cornea or lens at birth
  • additional factors such as eye injury, illness, or post-surgical complications contributing to its development
  • genetics, with familial studies demonstrating a heightened risk for offspring of astigmatic parents

Astigmatism can lead to blurred vision at all distances, making it difficult to see clearly and causing issues with night vision, such as increased glare from bright lights. However, wearing glasses or using prescription lenses can help improve vision and alleviate these symptoms. Timely recognition of astigmatism and other eye conditions necessitates regular eye examinations.

Man lifting his glasses off his nose and squinting to try to see something more clearly

Common Astigmatism Symptoms

Difficulty focusing on objects, eye strain, and headaches may be typical signs of astigmatism. These symptoms can impact daily activities, making tasks such as driving, using a computer, or even enjoying leisure activities like sports and reading more challenging. Astigmatism-related headaches and eye strain can be particularly bothersome, as the eyes have to strain to focus, leading to eye fatigue and discomfort.

Blurred or distorted vision can be a symptom of astigmatism, as the irregular shape of the cornea or lens can cause blurred or distorted vision. Early detection and intervention are crucial, as prompt treatment can help improve vision and alleviate these symptoms, ensuring better overall eye health and quality of life.

Potential Causes of Astigmatism

As previously noted, genetics, eye injuries, or certain eye diseases may contribute to astigmatism. Genetics play a role in the development of astigmatism, with family studies demonstrating a major role for genetics, with children of astigmatic parents being at an increased risk. Gene-based analysis has also identified candidate genes associated with astigmatism, although the genetic susceptibility to astigmatism is still not fully understood.

Eye injuries may also potentially result in astigmatism due to alterations in the curvature of the lens inside the eye or harm to the cornea. Specific ocular diseases, such as keratoconus and lenticular astigmatism, can also lead to astigmatism, as well as emerging after an eye trauma or operation.

Irrespective of the cause, optimal eye health hinges on early detection and appropriate treatment.

Diagnosing Astigmatism: The Importance of Eye Exams

Regular eye examinations are of paramount importance for diagnosing astigmatism, involving tests for visual acuity, corneal curvature, and light refraction. These tests enable eye doctors to accurately assess the presence and severity of astigmatism, allowing for the implementation of appropriate corrective measures, such as the use of corrective lenses or refractive surgery, to enhance vision clarity and eye comfort.

Phoropter in black & white

By diagnosing astigmatism early, patients can benefit from prompt treatment and management of the condition, helping to avert vision loss and improve overall eye health. In the following sections, we will delve into the specific diagnostic tests used in the assessment of astigmatism.

Visual Acuity Test

A visual acuity test, which evaluates the sharpness of one’s vision, can aid in detecting astigmatism. Conducted using an eye chart, such as the Snellen chart, this test evaluates one’s ability to see at various distances. The test results are expressed as a fraction, with 20/20 vision indicating normal sharpness or clarity of vision.

While a visual acuity test cannot give a definitive diagnosis of astigmatism, it provides essential information in assessing one’s vision capabilities. For a more accurate diagnosis, a comprehensive eye examination, including additional tests such as corneal topography and refraction assessment, is necessary.

Refraction Assessment

A refraction assessment is essential in diagnosing astigmatism, as it assists in establishing the precise prescription required to rectify the irregular curvature of the cornea or lens, which is the primary cause of astigmatism. By measuring the refractive error of the eye, the assessment can precisely diagnose and quantify the extent of astigmatism present.

A number of factors may influence the results of a refraction assessment, including refractive errors, such as:

Despite these factors, the refraction assessment remains a reliable method for measuring the degree of astigmatism and determining the appropriate corrective measures needed for improved vision. This might sound very detailed and complex, but don’t worry, here at Eye Expressions, we have extensive experience in diagnosing and treating astigmatism. We’re just explaining a lot of detail here for interest’s sake.

Corneal Topography

The procedure of corneal topography maps the cornea’s surface to detect any irregularities potentially causing astigmatism. It involves creating a computerized image of the cornea to identify any irregularities in its curvature. This technique is utilized to diagnose astigmatism and can also detect other conditions such as malignant growths. Furthermore, corneal topography assists ophthalmologists in selecting more appropriate contact lenses.

The corneal topography procedure is:

  • Expeditious
  • Painless
  • Noninvasive
  • Takes only a few seconds to complete

It is a fundamental tool for evaluating and monitoring astigmatism, as well as other eye conditions that may impact the cornea’s shape and curvature.


Treating Astigmatism: Finding the Right Solution

Astigmatism treatment options encompass corrective lenses, gas permeable contact lenses, and refractive surgery. Depending on the severity of astigmatism and the specific needs of the individual, one or more of these options may provide the best solution for improved vision.

In this section, we will explore these treatment options and their suitability for different cases of astigmatism.

Optometrist interacting with a patient
Woman with glasses reading a book comfortably, thanks to her correclty prescribed glasses

Corrective Lenses: Glasses and Toric Lenses

Astigmatism can be corrected by glasses with cylindrical lenses or contact lenses called toric lenses, which compensate for the irregular corneal shape. Glasses for astigmatism can markedly clarify vision, while toric contact lenses are specifically designed to address astigmatism by weighting the contact lens to sit correctly on the eye, enabling light to focus accurately on the retina and furnishing clearer vision.

The prescription for astigmatism glasses is determined by the cylinder (CYL) and axis values specified in the prescription. The cylinder value indicates the degree of astigmatism correction required, while the axis value determines the orientation of the astigmatism correction. This tailored approach ensures that each individual receives the most effective corrective lenses for their unique vision needs

Gas Permeable Contact Lenses

Also referred to as rigid gas permeable (RGP) lenses, gas permeable contact lenses are hard contact lenses made from silicone. They are oxygen-permeable, permitting air to pass through and providing enhanced breathability for the eyes compared to soft contact lenses. GP lenses are tailored to each patient based on their eye’s individual curvature, size, and corneal shape.

Gas permeable contact lenses operate in correcting astigmatism by offering a consistent and rigid surface that assists in clearer vision. These lenses can provide clearer vision for those with astigmatism, especially in severe cases where soft lenses may not be sufficient for optimal vision correction.

A woman putting in a contact lens
Laser eye view through surgical laser scope

Refractive Surgery Options: LASIK and PRK

Refractive surgery options like LASIK and PRK can correct astigmatism by reshaping the cornea. Both of these procedures involve the use of a specialized laser to alter the curvature of the cornea, making it more balanced and correcting the irregular curvature that causes astigmatism.

LASIK and PRK are recommended for astigmatism treatment when an individual has astigmatism in combination with nearsightedness or farsightedness. Both LASIK and PRK are capable of effectively correcting astigmatism and providing satisfactory outcomes.

PRK may be recommended for those who are ineligible for LASIK or have extremely high astigmatism.

Professional Care for Astigmatism in Lloydminster: Dr. Jade and Dr. Sarah at Eye Expressions Optical

A photo of dr. Sarah and dr. Jade

At Eye Expressions Optical, Dr. Jade and Dr. Sarah are experienced professionals specializing in diagnosing and treating astigmatism, as well as assessing and recommending eye surgery options when appropriate. They provide personalized care and treatment options tailored to each patient’s unique vision needs, ensuring optimal results in addressing astigmatism and other vision problems.

Whether you require eyeglasses, contact lenses or would like pre-Lasik or post-Lasik refractive surgery, you can trust Dr. Jade and Dr. Sarah to guide you toward the most effective solution for your individual needs.


Astigmatism is a common vision problem that can impact our daily lives, making it crucial to understand its causes, symptoms, and treatment options. By undergoing regular eye exams, seeking prompt diagnosis, and exploring various treatment options such as corrective lenses or refractive surgery, individuals with astigmatism can experience improved vision and enjoy a higher quality of life. Don’t let astigmatism hold you back – take control of your vision and embrace the clarity that comes with expert care and personalized treatment.

Frequently Asked Questions


What is the main cause of astigmatism?

Astigmatism is caused by an irregular shape of the cornea or lens, resulting in light bending differently as it enters the eye. There is no known cause or prevention for this refractive error.

How does a person with astigmatism see?

For people with astigmatism, when looking at objects, light that enters the eye is bent more than it should be, so only parts of the object are in focus, causing them to look blurry or wavy. Often vertical lines will be more out of focus than horizontal lines.

Is astigmatism a type of poor eyesight?

Astigmatism is a common type of refractive error caused by an altered eye shape that makes vision blurry. It can cause blurry vision in both close and far distances, as well as headaches, eye strain, and fatigue, but can be treated with corrective lenses like eyeglasses or contact lenses.

How is astigmatism diagnosed?

Astigmatism is typically diagnosed through a comprehensive eye exam, including visual acuity testing, corneal topography, and refraction assessment.

What are the treatment options for astigmatism?

Treatment options for astigmatism include corrective lenses (glasses or toric contact lenses), gas permeable contact lenses, and refractive surgery (LASIK or PRK).