What Is Astigmatism and How Is It Corrected?
Understanding Astigmatism
Astigmatism is a refractive error caused by an uneven curvature of the cornea, the clear front surface of your eye. In an eye without astigmatism, the cornea is rounded evenly in all directions, allowing light to focus at a single point on the retina, which is the light-sensitive tissue at the back of the eye. When astigmatism is present, the cornea curves more steeply in one direction than the other. This uneven shape causes light to split into multiple focal points, resulting in blurred or distorted vision at any distance.
Regular astigmatism is the most common form, occurring when the two principal meridians of the cornea are perpendicular to each other. This type responds well to correction with glasses, contact lenses, or refractive surgery. Irregular astigmatism involves meridians that are not perpendicular and may result from corneal scarring, keratoconus (a condition where the cornea thins and bulges into a cone shape), or previous eye surgery. Irregular astigmatism often requires specialty contact lenses or more advanced surgical approaches.
Our optometrist classifies astigmatism by where light focuses relative to the retina. Myopic astigmatism occurs when one or both focal points fall in front of the retina, combining astigmatism with nearsightedness. Hyperopic astigmatism occurs when one or both focal points fall behind the retina, combining astigmatism with farsightedness. Mixed astigmatism occurs when one focal point falls in front and the other behind the retina. Each type calls for a different lens prescription or surgical approach.
How Astigmatism Affects Your Vision
If you have astigmatism, you may experience blurry or distorted vision at both near and far distances. Straight lines may appear tilted or wavy. Other common symptoms include eye strain, headaches after prolonged reading or screen use, difficulty seeing clearly at night, and squinting to bring objects into focus. Many people have mild astigmatism without noticeable symptoms, which is why routine comprehensive eye exams are important for detecting changes over time.
Children may not recognize or communicate that their vision is blurry, making routine pediatric eye exams essential. Uncorrected astigmatism in young children can contribute to amblyopia (commonly called lazy eye) if one eye develops significantly more blur than the other. Early detection and correction help support healthy visual development. If you are concerned about your child's vision, our optometrist can perform a thorough evaluation to determine whether treatment for childhood astigmatism is needed.
Nearsightedness, also called myopia, causes distant objects to appear blurry while near vision stays clear. Farsightedness, also called hyperopia, makes close objects harder to see. Astigmatism blurs vision at all distances because of the uneven corneal shape rather than the overall length of the eye. It is common for astigmatism to occur alongside myopia or hyperopia, and your prescription will account for all refractive errors present in each eye.
Who Develops Astigmatism
Most astigmatism is present from birth and tends to run in families. The shape of the cornea is largely determined by genetics, which is why many children inherit some degree of astigmatism from their parents. In most cases the amount of astigmatism remains relatively stable throughout life, though it can shift gradually with age. You can learn more about how your prescription may change over time by reading about whether astigmatism progresses over time.
Certain conditions and events can cause astigmatism to develop or worsen later in life. Eye injuries, corneal diseases such as keratoconus, and scarring from infections or surgeries can all alter the shape of the cornea. Habitual eye rubbing has also been associated with progressive corneal changes. Understanding what causes astigmatism to worsen can help you take steps to protect your corneal health.
According to research from the National Eye Institute and a 2026 YouGov survey, roughly 75% of all adults need some form of vision correction, and astigmatism accounts for a significant share of those prescriptions. Many cases are mild enough that correction may not be necessary. However, even small amounts of uncorrected astigmatism can cause visual fatigue and discomfort, particularly during tasks that require sustained focus such as computer work or nighttime driving.
How Astigmatism Is Corrected
Glasses with a cylindrical lens component are the most common and straightforward way to correct astigmatism. Your prescription will include a cylinder value and an axis, which indicate the amount and orientation of astigmatism in each eye. Modern lens designs provide clear vision across the full field of view, and glasses can be updated easily as your prescription changes. For a full overview of correction methods, see our guide to astigmatism treatment options.
Toric contact lenses are specially designed to correct astigmatism. Unlike standard spherical lenses, toric lenses have different powers in different meridians and include stabilization features to keep the lens properly oriented on the eye. They are available in soft disposable, rigid gas permeable, and hybrid designs. Our eye doctor can help you find the most comfortable option during a toric contact lens fitting.
Laser vision correction procedures such as LASIK and PRK (photorefractive keratectomy, a procedure that removes the outer layer of the cornea before laser reshaping) can permanently reshape the cornea to correct astigmatism along with nearsightedness or farsightedness. During LASIK, a thin flap is created in the cornea and an excimer laser reshapes the underlying tissue to create a more uniform curvature. Both procedures offer strong outcomes for eligible candidates with stable prescriptions.
For patients undergoing cataract surgery, toric intraocular lenses (IOLs), which are artificial lenses implanted inside the eye, can correct astigmatism at the same time the clouded natural lens is replaced. This approach reduces or eliminates the need for astigmatism-correcting glasses after surgery. Our optometrist evaluates each patient's corneal measurements carefully to determine whether a toric IOL is appropriate and which power will provide the best visual outcome.
Orthokeratology, often called ortho-k, involves wearing specially designed rigid contact lenses overnight to gently reshape the cornea while you sleep. The effect is temporary, providing clear vision during the day without glasses or daytime contacts. Ortho-k can be effective for mild to moderate astigmatism and is also used as part of myopia management programs for children.
Frequently Asked Questions
Astigmatism itself does not damage the structures of the eye or lead to disease. However, leaving significant astigmatism uncorrected can result in ongoing eye strain, headaches, and difficulty performing daily tasks. In children, uncorrected astigmatism may contribute to amblyopia if not addressed early. Routine eye exams help ensure any changes are caught and corrected promptly.
Our eye doctor uses several tests to diagnose and measure astigmatism. A refraction test determines your exact prescription by having you compare lens options while viewing an eye chart. Corneal topography maps the surface curvature of your cornea in detail, and keratometry measures the steepest and flattest meridians. These measurements guide the selection of glasses, contacts, or surgical correction.
Glasses and contact lenses correct astigmatism only while you wear them, so prescriptions are typically updated every one to two years during regular eye exams. Laser procedures such as LASIK and PRK produce long-lasting results for most patients, though natural age-related changes in the eye can gradually shift your vision over the years. Toric IOLs placed during cataract surgery provide permanent astigmatism correction because the implanted lens does not change shape.
Both options effectively correct astigmatism, and the better choice depends on your preferences and lifestyle. Glasses are low-maintenance and easy to update, while toric contacts offer a wider field of view and freedom from frames during physical activities. Some patients with higher levels of astigmatism find that rigid gas permeable lenses provide sharper vision than soft toric lenses. Our optometrist can help you weigh the benefits of each approach during a comprehensive eye exam.
Standard vision insurance typically covers a portion of the cost for glasses or contact lenses prescribed to correct astigmatism. Medical insurance may cover astigmatism-related care when an underlying condition requires treatment. Laser vision correction and premium toric IOLs during cataract surgery are often considered elective and may not be fully covered, though financing options are frequently available.
What our Patients say
4.8
Reviews
(3,408)