What is Astigmatism? Can It Be Treated?
Astigmatism is extremely common, but because it can show up differently for everyone, it often leaves people confused or unsure about what’s going on with their eyesight.
In this guide, we’ll walk through what astigmatism really is, why it happens, how it affects the way you see the world, and the treatment options available.
Whether you’ve recently been diagnosed or just want to understand your eyes a little better, you’ll find everything you need right here.
What Is Astigmatism?
Astigmatism happens when the eye can’t focus light evenly onto the retina. Instead of creating a crisp, clear image, the eye bends light in different directions (kind of like a camera lens that’s slightly out of focus).
Photo courtesy of: Health Partners
This unevenness usually comes from an irregular shape in either:
The cornea (the clear front surface of the eye)
Or the lens inside the eye
Because of this irregular shape, light doesn’t land where it should, causing blurry, distorted, or stretched vision.
If you think about eye conditions in general:
Nearsightedness (myopia) = trouble seeing far
Farsightedness (hyperopia) = trouble seeing near
Astigmatism = trouble seeing clearly at any distance unless corrected
But don’t worry! Astigmatism is one of the most treatable vision conditions out there.
Here’s an analogy that makes it easier to understand:
A “normal” cornea is shaped like a basketball.
Perfectly round. Even curvature. Light enters smoothly and focuses on one point.
An astigmatic cornea is shaped more like a football.
Longer in one direction, shorter in another.
Light focuses on multiple points instead of one.
Even if you don’t notice the distortion right away, your eyes do, which is why eye strain and headaches are so common with untreated astigmatism.
Photo courtesy of: Perspective Eyes
Types of Astigmatism
Astigmatism isn’t one-size-fits-all. There are actually two main types, depending on where the irregularity occurs.
1. Corneal Astigmatism
This is the most common type. It happens when the cornea (the clear dome on the front of your eye) is oval-shaped instead of round.
Because the curvature varies across the cornea, light bends unevenly, creating distorted vision.
Symptoms may feel like:
- Blurred vision at all distances
- Difficulty switching focus
- Eye strain
- Squinting to see clearly
2. Lenticular Astigmatism
This type occurs inside the eye.
The lens behind the pupil has an irregular shape, even if the cornea is perfectly normal.
Lenticular astigmatism often causes the same symptoms as corneal astigmatism (blur, shadowy vision, or distortion), but requires slightly different correction depending on severity.
With-the-Rule vs. Against-the-Rule Astigmatism
Astigmatism can also be categorized based on the direction of the steepest curve of the cornea or lens.
With-the-Rule Astigmatism
- The cornea is steeper vertically
- More common in younger people
- Usually causes horizontal blur
- Think: the eye is more curved top-to-bottom
Against-the-Rule Astigmatism
- The cornea is steeper horizontally
- More common as we age
- Often causes vertical blur
- Think: the eye is more curved side-to-side
These natural shifts are part of why your prescription can change as you get older.
Common Symptoms of Astigmatism
Astigmatism can show up in different ways, but most people notice:
- Blurred or fuzzy vision
- Distortion (straight lines may look wavy)
- Eye strain or squinting
- Headaches
- Difficulty focusing for long periods
- Trouble seeing clearly at night (especially bright lines while driving at night)
- Dizziness or unsteadiness (in more severe cases)
Your eyes are constantly trying to compensate for the distorted image, which is what leads to the discomfort.
What Can Make Astigmatism Worse?
Astigmatism can be present from birth, but several factors can contribute to its development or cause it to worsen:
Genetics
Astigmatism often runs in families.
Eye injuries
Scratches, trauma, or scarring can alter the shape of the cornea.
Eye surgery
Procedures involving the cornea can sometimes change its curvature.
Aging
Corneal curvature naturally changes as we get older, often shifting astigmatism from with-the-rule to against-the-rule.
Regular eye exams help track these changes before they cause discomfort.
How Is Astigmatism Diagnosed?
Diagnosing astigmatism is simple and painless. Your eye doctor uses a combination of tests to understand the shape of your eye and how well it focuses light.
Some of these tests may include:
1. Visual Acuity Test
Reading letters on a chart at different distances.
2. Keratometry
Measures the curvature of your cornea using a circle of reflected light.
3. Refraction Test
The familiar “Which is better: 1 or 2?” test using a phoropter to find your exact prescription.
These tests, often used together, allow your eye doctor to determine the degree and type of astigmatism and recommend treatment.
Can Astigmatism Be Corrected? Absolutely.
Astigmatism has several reliable treatment options depending on your lifestyle and severity.
Eyeglasses
The simplest, most accessible fix.
Glasses use cylindrical lenses to compensate for the irregular shape of the cornea or lens.
Contact Lenses
Toric lenses are designed specifically for astigmatism.
They come in:
- Rigid gas permeable (RGP) versions
- Options for mild to severe cases
If you’re exploring contact lens options, Blue Planet Optics carries a full range of toric lenses.
Orthokeratology (Ortho-K)
A non-surgical method using special rigid lenses worn overnight. Ortho-K lenses temporarily reshape the cornea so you can see clearly during the day without glasses or contacts.
What Happens If Astigmatism Goes Untreated?
Living with untreated astigmatism can affect your daily life more than you might expect.
You may experience:
- Constant headaches
- Chronic eye fatigue
- Difficulty reading or focusing
- Night driving challenges
- Dizziness or imbalance
Because your eyes are always working overtime, untreated astigmatism can make everyday tasks feel exhausting.
Talk to Your Eye Doctor
Astigmatism is extremely treatable, and most people achieve clear, comfortable vision with the right correction method. If you’re noticing blurry/distorted vision or your symptoms seem to be getting worse, schedule an eye exam. Your doctor will help you understand your eyes and build a treatment plan that fits your life.
And if you want to learn more about contact lenses for astigmatism, toric lenses, or eye health in general, the Blue Planet Optics Blog is packed with helpful guides and tips.
Frequently Asked Questions
Can astigmatism cause dizziness?
Yes. Moderate to severe astigmatism can cause dizziness, headaches, and nausea because your eyes are constantly straining to focus.
What causes astigmatism?
It’s usually genetic, but injuries, surgery, and aging can also contribute.
How does astigmatism affect vision?
It causes blur, distortion, or “stretched” vision at all distances. Straight lines may appear wavy or shadowed.
Is astigmatism treatable?
Absolutely. Glasses, contacts, and Ortho-K lenses are all effective options.
Can astigmatism change over time?
Yes, it can worsen or shift with age. Regular eye exams help you stay ahead of these changes.
How does astigmatism affect children?
Untreated astigmatism in children can lead to “lazy eye” (amblyopia). Early detection is essential.