What Is Astigmatism? Symptoms, Causes & Correction

Astigmatism is a common refractive error caused by an irregularly shaped cornea or lens. It can make vision blurry or distorted at any distance and may cause headaches, eye strain, or difficulty seeing at night. Glasses, contact lenses, and selected procedures can correct astigmatism effectively.

What is astigmatism?

Astigmatism occurs when the front surface of the eye, usually the cornea, has a more oval shape instead of being evenly round. This changes how light focuses on the retina, producing blurred or stretched images.

It may occur alone or alongside nearsightedness or farsightedness. An eye examination is the best way to identify astigmatism and measure its severity. If you are due for a check-up, learn more about our eye exam services .

What are the symptoms of astigmatism?

Common astigmatism symptoms include:

• Blurred or distorted vision at near or far distances
• Headaches after reading or screen use
• Eye strain or tired eyes
• Squinting to see more clearly
• Difficulty seeing at night or around bright lights

Symptoms can be mild and easy to overlook. Children may not describe blurred vision, so regular eye exams are especially important for them.

What causes astigmatism?

The most common cause is the natural shape of the cornea or lens. Some people are born with astigmatism, while others develop changes over time. Eye injury, surgery, or certain corneal conditions can also affect its shape.

Astigmatism is not caused by reading in poor light or sitting too close to a screen. However, prolonged visual tasks may make its symptoms more noticeable.

How is astigmatism diagnosed?

An optometrist can detect astigmatism during a comprehensive eye examination. Testing may include a visual acuity chart, refraction assessment, and measurements of the cornea. These results determine whether correction is needed and which prescription is appropriate.

How is astigmatism corrected?

Treatment depends on your prescription, lifestyle, and eye health. Common options include:

1. Prescription glasses: A simple, safe solution for clear everyday vision.
2. Toric contact lenses: Specially designed lenses that compensate for uneven focusing.
3. Orthokeratology: Rigid lenses worn overnight in selected cases to temporarily reshape the cornea.
4. Refractive surgery: Procedures such as laser vision correction may be appropriate for some adults.

Your optometrist should recommend the safest option after evaluating your eyes. Never share contact lenses or use an old prescription without professional advice.

When should you schedule an eye exam?

Book an appointment if blurry vision, headaches, eye strain, or night-vision problems persist. Seek urgent care after sudden vision loss, severe eye pain, flashes, or a rapid increase in floaters. You can contact the clinic to discuss your symptoms and arrange an evaluation.

Key takeaways

Astigmatism is a common focusing problem linked to the shape of the cornea or lens. It can cause blurred vision, headaches, and eye strain, but it is usually manageable. Glasses and contact lenses are the most common corrections, while other options may suit selected patients. The next step is a comprehensive eye exam to confirm the diagnosis, measure your prescription, and choose appropriate correction. If symptoms are affecting reading, work, driving, or night vision, schedule an appointment rather than delaying care.