Astigmatism
What Is Astigmatism and What Causes It?
When you have astigmatism, light does not focus on a single point at the back of your eye. Instead, it scatters into multiple points, creating a blurred or stretched image. You may notice that straight lines appear wavy, or that objects look smudged no matter how close or far they are.
People with astigmatism often squint to try to see more clearly. This extra effort can lead to eye strain and headaches, especially after reading or using a computer for a long time.
Most people are born with some degree of astigmatism because of the natural shape of their cornea. The condition often runs in families, so if your parents have it, you may develop it as well. In some cases, astigmatism can develop after an eye injury, certain eye diseases, or surgery on the eye.
- Genetic factors passed down from parents
- The natural curve of the cornea present from birth
- Eye injuries that change the shape of the cornea
- Keratoconus, a condition where the cornea thins and bulges
We classify astigmatism based on which part of your eye has the irregular curve. Corneal astigmatism means the front surface of your eye is not evenly rounded. Lenticular astigmatism occurs when the lens inside your eye has an uneven shape instead.
You may also hear the terms regular and irregular astigmatism. Regular astigmatism is the most common type and is easy to correct with standard glasses or contact lenses. Irregular astigmatism, which may result from scarring or certain eye conditions, often requires specialty lenses or other treatments.
Anyone can develop astigmatism, but certain factors make it more likely. Children with a family history of the condition have a higher chance of needing correction early in life. People with other refractive errors, such as nearsightedness or farsightedness, often have astigmatism at the same time.
- Individuals with parents or siblings who have astigmatism
- Those with nearsightedness or farsightedness
- People who have had eye trauma or corneal scarring
- Patients with certain conditions like keratoconus
Recognizing the Signs of Astigmatism
The hallmark symptom of astigmatism is blurry vision that does not improve when you move closer or farther from an object. You might notice that letters look tilted, edges appear fuzzy, or straight lines seem curved. This happens because light entering your eye focuses unevenly on your retina.
Unlike simple nearsightedness, where only distant objects blur, or farsightedness, where close-up tasks are harder, astigmatism can affect your clarity at every range. Many people do not realize they have it until a routine eye exam reveals the problem.
Your eyes work overtime to compensate for the distorted images caused by astigmatism. This constant effort can leave your eyes feeling tired, sore, or dry, especially after reading, working on a computer, or driving. You may also develop frequent headaches around your forehead or temples.
- Aching or burning sensation in the eyes
- Headaches after visual tasks like reading or screen time
- Difficulty concentrating on detailed work
- Feeling unusually tired at the end of the day
Many people with astigmatism find that their vision worsens in low light or at night. Streetlights, car headlights, and other bright points may appear to have starbursts or long streaks radiating outward. This happens because your pupils open wider in dim conditions, allowing more unfocused light to enter your eye.
Night driving can become especially challenging when oncoming headlights create glare and halos. If you notice these symptoms, let us know so we can check your prescription and discuss ways to improve your night vision.
Most astigmatism develops slowly and does not require urgent attention. However, sudden changes in your vision, severe eye pain, flashes of light, or a curtain-like shadow over your field of view are warning signs of serious conditions. If you experience any of these symptoms, contact us or visit an emergency eye care provider right away.
Rapid worsening of blurry vision or new distortion in one eye may signal a problem beyond simple astigmatism. We can evaluate your symptoms and determine whether you need immediate treatment or further testing.
How We Diagnose Astigmatism
Diagnosing astigmatism begins with a thorough eye exam. We will ask about your symptoms, family history, and any vision problems you have noticed. Then we check your visual acuity, test how your eyes work together, and examine the health of the front and back of your eyes.
- Reviewing your medical and family eye history
- Checking your ability to see clearly at different distances
- Assessing eye alignment and movement
- Examining the cornea, lens, and retina for signs of disease
A refraction test helps us determine the exact lens prescription you need to see clearly. You will look through a device called a phoropter while we flip different lenses in front of your eyes. We will ask you to compare which lens makes the letters on the chart look sharper.
This test measures not only how much astigmatism you have but also whether you are nearsighted or farsighted. The results guide us in prescribing the right eyeglasses or contact lenses to correct all of your refractive errors at once.
To understand the shape of your cornea, we use an instrument called a keratometer or corneal topographer. This device shines light onto your cornea and measures how it reflects back. The pattern tells us where your cornea is steeper or flatter than normal.
Corneal mapping is especially useful if you are considering contact lenses or refractive surgery. It shows us the precise contours of your eye so we can recommend the best correction method for your unique shape.
Your eyeglass or contact lens prescription includes three main numbers for each eye. The first number indicates nearsightedness or farsightedness. The second number, called the cylinder, measures the amount of astigmatism. The third number, the axis, shows the direction of the irregular curve on your cornea.
- Sphere value for nearsightedness or farsightedness
- Cylinder value for the degree of astigmatism
- Axis number showing the angle of astigmatism in degrees
- Additional values for reading needs if you require multifocal lenses
Treatment Options for Astigmatism
Eyeglasses are the simplest and most common way to correct astigmatism. Your lenses will have a special cylindrical curve built in to counteract the irregular shape of your cornea. Once you put on your glasses, light will focus correctly on your retina, making your vision clear and comfortable.
Modern lens technology can address even high levels of astigmatism while keeping your glasses thin and lightweight. We can also add coatings to reduce glare, protect against blue light, or darken in bright sunlight for added convenience.
If you prefer contact lenses, toric lenses are designed specifically to correct astigmatism. These lenses have different powers in different parts of the lens and are weighted or shaped to stay in the correct position on your eye. We will measure your cornea carefully to ensure a proper fit.
- Soft toric lenses for mild to moderate astigmatism
- Rigid gas permeable lenses for higher or irregular astigmatism
- Hybrid lenses combining a rigid center with a soft outer skirt for comfort
- Scleral lenses that vault over the cornea for complex cases
Laser vision correction can permanently reshape your cornea to reduce or eliminate astigmatism. Procedures such as LASIK and PRK use a laser to remove tiny amounts of corneal tissue, smoothing out the irregular curve. In 2025, advanced imaging and wavefront technology allow us to create highly customized treatment plans tailored to your eye.
Not everyone is a candidate for laser surgery. We will evaluate the thickness and health of your cornea, the stability of your prescription, and your overall eye health before making a recommendation. Alternative procedures, such as implantable lenses, may be considered in specific cases for patients who are not good candidates for laser treatment.
If your astigmatism is very mild and does not interfere with your daily activities, we may suggest monitoring your vision over time instead of prescribing correction right away. Many people have small amounts of astigmatism that do not cause noticeable symptoms or affect their quality of life.
We will schedule regular eye exams to check whether your astigmatism changes or begins to impact your comfort and vision. If you start to experience blurry vision, headaches, or eye strain, we can prescribe glasses or contact lenses at that time.
Managing Your Astigmatism Day to Day
It may take a few days for your eyes and brain to adjust to your new prescription, especially if this is your first time wearing correction for astigmatism. You might notice that straight lines look different or that depth perception feels slightly off at first. These sensations are normal and usually go away within a week or two.
Wear your new glasses or contacts as much as possible during the adjustment period. If discomfort, dizziness, or blurry vision persists beyond two weeks, contact our office so we can check the fit and accuracy of your prescription.
Taking good care of your contact lenses is essential to keeping your eyes healthy. Always wash your hands before handling your lenses, and use fresh solution each time you store them. Never sleep in your contacts unless they are specifically approved for overnight wear, and replace them according to the schedule we give you.
- Clean and rinse lenses with recommended solution every day
- Replace your lens case every three months
- Never use tap water or saliva on your contacts
- Remove lenses immediately if your eyes become red, painful, or irritated
- Follow the replacement schedule for daily, biweekly, or monthly lenses
We typically recommend comprehensive eye exams every one to two years for adults with stable astigmatism. Children and teenagers may need more frequent visits because their eyes are still growing and their prescriptions can change quickly. If you wear contact lenses, annual exams help us monitor the health of your cornea and update your lens fit as needed.
Patients with certain eye conditions or those considering refractive surgery may need exams more often. We will create a personalized follow-up schedule based on your age, eye health, and vision needs.
Even with correction, your astigmatism can change gradually over the years. Pay attention to any new blurriness, increased glare, or difficulty with tasks that used to be easy. If your current glasses or contacts no longer provide clear vision, schedule an appointment so we can update your prescription.
Sudden changes in vision may signal other eye problems beyond astigmatism. Let us know right away if you notice flashes of light, floating spots, loss of side vision, or any other unusual symptoms so we can evaluate your eyes promptly.
Frequently Asked Questions
Yes, astigmatism can change as you age, though it often remains stable for many years. Your cornea may shift shape slightly over time, or conditions like keratoconus can cause the astigmatism to increase. Regular eye exams allow us to track any changes and update your correction as needed to keep your vision sharp.
Some children experience a small reduction in astigmatism as their eyes grow and develop, but most do not outgrow it completely. Early correction with glasses or contact lenses is important to ensure clear vision during critical learning years and to prevent amblyopia, sometimes called lazy eye. We will monitor your child's prescription and adjust treatment as their eyes mature.
Astigmatism itself does not lead to permanent vision loss or blindness. It is a refractive error, not an eye disease. However, if left uncorrected in childhood, it can contribute to amblyopia, which may result in reduced vision that is harder to treat later. Wearing the right prescription protects your long-term eye health and visual development.
No, astigmatism is a separate refractive error caused by an irregularly shaped cornea or lens, while nearsightedness and farsightedness result from the overall length of the eyeball. Many people have astigmatism along with nearsightedness or farsightedness, and a single pair of glasses or contact lenses can correct all three conditions at once.
The uneven curve of your cornea scatters light rays in multiple directions instead of focusing them to a single point. This creates the appearance of starbursts, streaks, or halos around bright lights, especially at night when your pupils are larger. Correcting your astigmatism with glasses, contacts, or surgery usually reduces or eliminates these visual distortions.
Getting Help for Astigmatism
If you are experiencing blurry vision, eye strain, or difficulty seeing clearly at any distance, we encourage you to schedule a comprehensive eye exam. Our eye doctor will measure your vision, assess the shape of your cornea, and recommend the best correction option for your lifestyle and needs. With the right treatment, you can enjoy clear, comfortable vision every day.