Astigmatism
What Is Astigmatism and What Causes It?
In a perfectly shaped eye, the cornea and lens are smooth and curved equally in all directions, like a basketball. With astigmatism, the cornea or lens has a different curve in one direction than the other, more like a football. This irregular shape prevents light from focusing properly on the back of your eye, which means images at near and far distances can appear blurry or stretched.
Because light rays do not meet at a single point, your brain receives distorted visual information. The result is that straight lines may look wavy, text may appear unclear, and both close-up and distant objects can seem out of focus at the same time. Astigmatism commonly occurs together with nearsightedness or farsightedness, and your correction will address the combined prescription.
Most cases of astigmatism are present from birth and tend to run in families. If your parents have astigmatism, you are more likely to develop it as well. Other causes include eye injuries, certain eye surgeries, or conditions that affect the shape of your cornea, such as keratoconus or pterygium.
- Family history of astigmatism or other refractive errors
- Eye trauma or scarring on the cornea
- Previous eye surgery or disease affecting the corneal surface
- Chronic eye rubbing or eyelid pressure that may contribute to corneal changes
Regular astigmatism is the most common type and occurs when the cornea curves more in one direction than another, creating two principal meridians with different curvatures. This produces a characteristic pattern of blurred vision that we can easily correct with glasses, contact lenses, or laser surgery. Irregular astigmatism happens when the corneal surface is uneven in multiple directions, often due to injury, scarring, or conditions like keratoconus.
Irregular astigmatism is harder to correct with standard glasses and may require specialized contact lenses or other advanced treatments. Astigmatism can also arise from the lens inside your eye rather than the cornea, though this is less common. Our eye doctor will determine which type you have during your comprehensive eye exam.
Signs You May Have Astigmatism
The hallmark sign of astigmatism is blurred or distorted vision that affects objects both near and far. You might notice that letters appear fuzzy, lines look wavy, or images seem stretched in one direction. Unlike nearsightedness or farsightedness, which mainly affect one distance, astigmatism can make everything look unclear.
This distortion happens because your eye focuses light unevenly, so no single focal point gives you a crisp image. Even mild astigmatism can make reading, using a computer, or recognizing faces more difficult than it should be.
When your eyes struggle to focus clearly, the muscles around them work harder to compensate. This extra effort can lead to tired, achy eyes, especially after reading or looking at a screen. Many people with uncorrected astigmatism also experience frequent headaches, particularly across the forehead or temples.
- Squinting to try to see more clearly
- Frequent headaches after visual tasks
- Sore or tired eyes by the end of the day
- Difficulty concentrating on reading or detailed work
Astigmatism often becomes more noticeable in low light conditions. You may see halos, starbursts, or streaks around streetlights and car headlights, making nighttime driving challenging and uncomfortable. These visual effects occur because your irregularly shaped cornea scatters incoming light in multiple directions.
Reduced contrast sensitivity is another common issue, making it harder to distinguish objects against similar backgrounds in dim lighting. If you avoid driving at night because of poor vision, astigmatism could be the cause.
While astigmatism itself is not an emergency, sudden changes in your vision require prompt attention. Seek urgent same-day evaluation if you experience a rapid increase in blurriness, sudden onset of double vision, sudden loss of vision in one eye, a curtain or shadow moving across your field of vision, flashes of light, a sudden increase in floaters, or any significant eye pain or redness with decreased vision. If these symptoms occur after hours, go to an emergency room for immediate care.
Do not drive if your vision is suddenly impaired. These symptoms could signal a serious condition, such as retinal detachment, acute glaucoma, infection, or corneal injury that needs urgent treatment. Even if your vision changes gradually, schedule an exam so we can monitor your eye health and update your prescription as needed.
How We Diagnose Astigmatism
Diagnosing astigmatism is straightforward and usually painless during a routine comprehensive eye exam. We will ask about your symptoms, medical history, and any vision problems you have noticed. Then we will perform a series of tests to measure how your eyes focus light and determine the exact shape of your cornea.
- Visual acuity testing to measure your clarity of vision
- Refraction assessment to find the right lens prescription
- Keratometry or corneal topography to map corneal curvature
- A full health check of your eye structures
During a refraction test, you will look through a device called a phoropter (an instrument that holds different lenses) while we show you a series of lens choices. We will ask which lenses make the eye chart clearer, helping us zero in on the exact prescription that corrects your astigmatism. This test carries very low risk and gives us precise measurements of your refractive error.
We may also use an automated instrument called an autorefractor to get an initial reading of your prescription. This device shines light into your eye and measures how it changes as it bounces off the back of your eye, offering a quick starting point for the manual refraction.
For a detailed view of your corneal shape, we may use corneal topography or tomography (imaging technologies that map the surface and internal structure of your cornea). These tools create a color-coded map of your cornea, revealing even tiny irregularities in its curvature. This information is especially helpful if you are considering laser vision correction or if we suspect irregular astigmatism.
Advanced imaging allows us to customize your treatment plan and track changes over time. If you have conditions like keratoconus, these maps help us monitor progression and recommend the most effective correction options for your unique eye shape.
Non-Surgical Treatment Options for Astigmatism
Eyeglasses are the simplest and most common way to correct astigmatism. Your lenses will have a special cylindrical prescription that compensates for the uneven curvature of your cornea or lens. The prescription includes the cylinder power (the degree of astigmatism) and axis (the orientation of the correction), which tells the lab exactly how to shape your lenses to give you the clearest vision.
We may recommend that you wear your glasses full time or just for specific activities like reading, computer work, or driving. Most people adapt to their new glasses quickly and notice improved clarity and comfort, though it may take a few days to a week for your brain to fully adjust to the correction.
If you prefer contact lenses, toric soft lenses are designed specifically to correct astigmatism. These lenses have different powers in different meridians and a built-in stabilization system to keep them properly oriented on your eye. For higher or irregular astigmatism, rigid gas permeable lenses, scleral lenses, or hybrid lenses can provide sharper vision and are particularly useful for conditions like keratoconus.
- Soft toric lenses for mild to moderate astigmatism
- Rigid gas permeable lenses for higher or irregular astigmatism
- Scleral lenses that vault over the cornea for complex prescriptions or irregular corneas
- Hybrid lenses combining a rigid center with a soft skirt for comfort and clarity
- Daily disposable or monthly replacement options
Extended-wear lenses, which may be worn overnight, are only appropriate when specifically prescribed and carry a higher risk of serious eye infection. Proper contact lens hygiene is essential to protect your eye health. Always wash your hands before handling lenses, never sleep in lenses unless directed by our eye doctor, avoid exposing lenses to water, and replace your lens case regularly.
Orthokeratology, or Ortho-K, involves wearing specially designed rigid contact lenses overnight to temporarily reshape your cornea while you sleep. When you remove the lenses in the morning, you can see clearly throughout the day without glasses or contacts. This non-surgical option is reversible and can be especially appealing for children or adults who are not ready for surgery.
Because the reshaping effect is temporary, you will need to wear the lenses regularly, typically most nights, to maintain clear daytime vision. Ortho-K requires a custom fitting, strict hygiene, and regular follow-up visits to monitor the corneal shape and ensure safe, effective correction. As with any overnight lens wear, there is an increased risk of eye infection, so careful cleaning and adherence to your wearing schedule are critical.
Surgical Treatment Options for Astigmatism
LASIK is a popular laser eye surgery that reshapes your cornea to correct astigmatism, along with nearsightedness or farsightedness. During the procedure, we create a thin flap in the cornea, use a laser to remove microscopic amounts of tissue, and then reposition the flap. Many patients achieve significantly improved vision and reduced dependence on glasses or contacts.
Good candidates for LASIK typically need stable vision, adequate corneal thickness, and realistic expectations. Not all levels or types of astigmatism can be fully corrected with LASIK, and irregular astigmatism is often not suitable for this procedure. We will carefully evaluate your eye health using corneal topography or tomography to assess your risk of ectasia (corneal thinning), check for dry eye, and determine if LASIK is a safe and effective option for you.
Photorefractive keratectomy, or PRK, is another laser vision correction option that reshapes the cornea without creating a flap. Instead, we gently remove the outer layer of the cornea before applying the laser. PRK may be a better choice if you have thinner corneas or certain lifestyle factors that make LASIK less ideal.
Other refractive procedures include LASEK and SMILE (small incision lenticule extraction). SMILE is commonly used for myopia with astigmatism, though its availability for other types of prescriptions may vary by location and technology. In select cases, topography-guided or wavefront-guided treatments can address certain corneal irregularities, though candidacy depends on the specific pattern and degree of astigmatism. Our eye doctor will discuss the benefits and recovery time of each option to help you make an informed decision.
If you have both astigmatism and cataracts, we can correct both conditions during cataract surgery by implanting a toric intraocular lens. These specialized lens implants have built-in astigmatism correction and can reduce or eliminate your need for glasses after surgery. Toric lenses are carefully positioned during the procedure to align with your corneal curvature.
In some cases, we may combine cataract surgery with astigmatic keratotomy or limbal relaxing incisions, small precise cuts in the cornea that help reshape its curvature. These techniques allow us to address your astigmatism and restore clear vision in a single procedure. Your surgeon will discuss which approach is best for your prescription and eye anatomy.
Not everyone is a good candidate for refractive surgery. We may advise against surgery if you have unstable vision, certain corneal diseases, autoimmune conditions, or unrealistic expectations about the results. Pregnancy, nursing, or uncontrolled diabetes can also affect your eligibility.
- Very high or unstable prescriptions
- Thin or irregularly shaped corneas
- Active eye infections or inflammation
- Certain medical conditions that affect healing
- Age under 18, when eyes are still developing
Managing Astigmatism and Follow-Up Care
It may take a few days to adjust to your new astigmatism correction, especially if this is your first pair of glasses or if your prescription has changed significantly. You might notice some distortion at the edges of your lenses or slight dizziness at first. These sensations usually disappear as your brain adapts to the clearer, sharper images.
If discomfort persists beyond a week or your vision does not seem right, contact our office. A small adjustment to your prescription or lens fit can make a big difference in your comfort and clarity.
Astigmatism can change over time, so we recommend regular eye exams to monitor your prescription and overall eye health. Most adults should have a comprehensive exam every one to two years, while children and people with certain risk factors may need more frequent visits.
If you notice new blurriness, headaches, or eye strain between scheduled appointments, do not wait to call us. An updated prescription can restore your clear vision and prevent unnecessary discomfort.
Maintaining good eye health habits can help you get the most out of your astigmatism correction. Always wear your prescribed glasses or contacts as directed, follow proper contact lens hygiene, and protect your eyes from injury with safety glasses during sports or hazardous activities.
- Take regular breaks from screens to reduce eye strain
- Keep your hands and lenses clean to prevent infections
- Wear sunglasses with UV protection outdoors
- Eat a balanced diet rich in eye-healthy nutrients
- Avoid rubbing your eyes, as chronic rubbing may contribute to corneal shape changes and increase risk of conditions like keratoconus
Recovery time varies depending on the type of surgery you have. After LASIK, many patients notice improved vision within a day or two, though it may take several weeks for your vision to fully stabilize. PRK has a longer initial recovery period, with noticeable improvement over the first week and continued healing for a few months.
Most people experience temporary dry eye, glare, and halos around lights at night, especially in the first weeks after surgery. Less common but more serious risks include infection, inflammation, corneal ectasia, flap complications with LASIK, corneal haze with PRK, and the possibility of under-correction or over-correction. Some patients may still need glasses for certain tasks, particularly for reading as they age, and a small percentage may require an enhancement procedure to fine-tune the results.
We will schedule follow-up visits to monitor your healing, check your vision, and address any concerns. Understanding these possible outcomes helps you make an informed decision and set realistic expectations for your procedure.
Frequently Asked Questions
Astigmatism usually does not go away without treatment because it is caused by the physical shape of your cornea or lens. In rare cases, very mild astigmatism in young children may improve slightly as their eyes grow, but most people need glasses, contacts, or surgery for clear vision throughout their lives.
Astigmatism can remain stable for years, but it may also change gradually as you age or if you develop certain eye conditions. Regular eye exams allow us to track any changes and update your correction as needed to keep your vision sharp.
Standard spherical contact lenses do not correct astigmatism because they do not account for the uneven corneal curvature. You will need toric lenses, which are specifically designed to address astigmatism, or rigid gas permeable lenses that can mask irregular corneal shape.
Many vision insurance plans cover glasses and contact lenses for astigmatism correction, though coverage varies by plan. Refractive surgery is often considered elective and may not be covered, but some plans offer discounts or flexible spending options to help with costs.
Yes, children can and should have astigmatism corrected to support healthy visual development and academic success. Significant uncorrected astigmatism in early childhood can lead to amblyopia (lazy eye), so timely correction and regular follow-up are important. We typically prescribe glasses for young children, and as they grow, they may transition to contact lenses if desired. Refractive surgery is generally not recommended until the late teens or early twenties when the eyes have finished growing.
Getting Help for Astigmatism
If you are experiencing blurry vision, headaches, or eye strain, we encourage you to schedule a comprehensive eye exam. Our eye doctor will diagnose your astigmatism, discuss your lifestyle and vision goals, and recommend the best correction options to help you see clearly and comfortably every day.