Understanding Astigmatism and How It's Corrected

Astigmatism is a refractive error caused by an irregularly shaped cornea or lens inside your eye. In a perfectly shaped eye, the cornea is round like a basketball, allowing light to focus evenly on the retina. With astigmatism, the cornea is shaped more like a football—curved more steeply in one direction than the other.

This uneven curvature causes light to focus on multiple points rather than a single point on the retina, resulting in blurred or distorted vision at all distances. You might notice that vertical lines appear clearer than horizontal ones, or vice versa. Some people describe their vision as stretched or skewed.

Astigmatism often occurs alongside other refractive errors like nearsightedness (myopia) or farsightedness (hyperopia). It can be present from birth or develop gradually over time. The severity can range from mild (which may not require correction) to significant (causing notable vision problems).

Astigmatism symptoms can be subtle, especially in mild cases. Many people adapt to their blurred vision without realizing something is wrong. However, recognizing these signs can help you seek timely care:

• Blurred or distorted vision at all distances, both near and far
• Eye strain or discomfort, particularly after prolonged reading or screen time
• Headaches, especially frontal headaches that worsen with visual tasks
• Difficulty seeing at night or in low-light conditions
• Squinting to try to see more clearly
• Halos or starbursts around lights, particularly noticeable when driving at night

Children with astigmatism may have trouble concentrating in school, complain of tired eyes, or avoid reading and other close-up activities. If your child frequently rubs their eyes, sits too close to the television, or tilts their head to see better, an eye exam is recommended.

Diagnosing astigmatism requires a comprehensive eye examination. Your eye care provider will use several tests to measure how your eyes focus light and determine the exact prescription needed to correct your vision.

A visual acuity test measures how clearly you see at various distances using the familiar eye chart. Keratometry measures the curvature of your cornea by focusing a circle of light on it and measuring its reflection. Refraction testing uses a phoropter—the instrument with multiple lenses—to determine which lens combination gives you the sharpest vision.

Advanced diagnostic tools like corneal topography create detailed maps of your cornea's surface, measuring thousands of points to detect even subtle irregularities. This technology is particularly useful for fitting specialty contact lenses or planning refractive surgery.

The American Optometric Association recommends comprehensive eye exams every two years for adults under 60, and annually for those over 60 or with risk factors. Children should have their first exam at six months, again at age three, and before starting school.

The good news is that astigmatism is highly correctable. Your eye care provider will recommend the best option based on the severity of your astigmatism, your lifestyle, and your personal preferences.

Eyeglasses

Eyeglasses are the simplest and most common way to correct astigmatism. Lenses for astigmatism are called "toric" lenses, which have different powers in different meridians of the lens to compensate for the uneven shape of your cornea. Modern lens technology provides excellent clarity, and glasses offer the added benefit of protecting your eyes from UV rays and digital eye strain.

Contact Lenses

Toric contact lenses are specifically designed to correct astigmatism. These lenses have different powers in different zones and are weighted or designed to stay in a specific orientation on your eye. Options include soft toric lenses, rigid gas-permeable (RGP) lenses, and hybrid lenses that combine the comfort of soft lenses with the crisp vision of RGP lenses.

Some people with mild astigmatism may achieve adequate vision with standard spherical contact lenses. Your eye care provider can help determine which type is best for you.

Refractive Surgery

For those seeking a more permanent solution, refractive surgery can reshape the cornea to correct astigmatism. LASIK (laser-assisted in situ keratomileusis) uses a laser to create a thin flap in the cornea, then reshapes the underlying tissue. PRK (photorefractive keratectomy) reshapes the cornea's surface without creating a flap. Both procedures have excellent success rates for treating astigmatism.

LASEK and newer procedures like SMILE (small incision lenticule extraction) offer additional options depending on your specific corneal anatomy and degree of astigmatism. A thorough consultation and examination will determine if you're a good candidate for surgery.

Orthokeratology

Ortho-k involves wearing specially designed rigid contact lenses overnight that temporarily reshape your cornea. 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 particularly popular for children with progressive myopia.

Once your astigmatism is properly corrected, you should experience clear, comfortable vision. However, there are steps you can take to maintain optimal eye health and ensure your correction continues to work effectively:

• Attend regular eye exams to monitor changes in your vision and update your prescription as needed
• Practice good lighting habits when reading or doing close work to reduce eye strain
• Follow the 20-20-20 rule: Every 20 minutes, look at something 20 feet away for 20 seconds
• Protect your eyes from UV radiation with sunglasses rated for 100% UV protection
• Care for your glasses or contacts properly according to your provider's instructions
• Maintain overall health through proper nutrition, hydration, and management of systemic conditions like diabetes

It's important to note that astigmatism can change over time. Your prescription from five years ago may no longer provide optimal clarity. If you notice your vision becoming less clear, experience eye strain, or develop headaches, schedule an appointment for a comprehensive exam.

While astigmatism is common and not dangerous, uncorrected astigmatism can impact your quality of life. Blurred vision can affect your ability to work, drive safely, read comfortably, and enjoy hobbies. Children with uncorrected astigmatism may struggle academically or in sports.

Seek care if you experience:

• Sudden changes in vision quality
• Persistent eye strain or headaches
• Difficulty with night driving or seeing in low light
• Increasing need to squint or adjust reading distance
• Eye discomfort during or after visual tasks

Don't wait until your vision significantly impacts your daily life. Early detection and correction of astigmatism can prevent unnecessary discomfort and ensure you're seeing as clearly as possible.