Understanding Astigmatism: Causes, Effects on Vision, and Solutions
If you've been diagnosed with astigmatism or know someone who has, you might wonder what exactly it means. Astigmatism is one of the most common vision issues, and while it might sound intimidating, it's entirely manageable with the right knowledge and care.
Here, we’ll explore what astigmatism is, what causes it, how it affects sight, and what you can do about it.
What is Astigmatism?
Astigmatism is a refractive error caused by an irregular curvature of the cornea (the front surface of the eye) or the lens inside the eye. Ideally, the cornea and lens should be smoothly rounded, much like a basketball. In people with astigmatism, these surfaces are shaped more like a football or an egg, leading to uneven focus of light entering the eye. This irregular shape prevents light from focusing properly on the retina, which can cause blurry, distorted, or sometimes double vision.
Astigmatism can occur along with other refractive errors like myopia (nearsightedness) and hyperopia (farsightedness) but affects vision in unique ways because of its uneven light refraction.
What Causes Astigmatism?
Astigmatism often develops from birth, but it can also emerge later in life due to eye injuries, surgeries, or diseases that affect the shape of the cornea. Genetics play a significant role, as people with family members who have astigmatism are more likely to develop it themselves. Another interesting factor is that some people experience a mild form of astigmatism naturally as their eyes develop and age, often without noticeable effects on their vision.
How Does Astigmatism Affect Sight?
The main symptom of astigmatism is blurred or distorted vision, especially noticeable when looking at objects both near and far. Additional symptoms can include:
Eye strain and discomfort after reading or doing tasks that require close focus
Headaches from prolonged screen time or near work
Squinting to see clearly, which can exacerbate eye strain
Difficulty with night vision due to light scatter, causing halos around lights
The severity of these symptoms can range from mild to significant, depending on the degree of astigmatism. For some, astigmatism can be unnoticeable, while others may find it very disruptive in daily tasks.
How is Astigmatism Diagnosed?
Astigmatism is usually diagnosed during a comprehensive eye exam. During this exam, an eye care professional may perform a series of tests, including a refraction test to determine the lens prescription and a keratometry or topography exam to measure the curvature of the cornea. These tests help create a complete picture of the refractive error and determine the best course of action to correct it.
What Can You Do About Astigmatism?
The good news is that there are multiple options for managing and correcting astigmatism. Here’s a look at the most common solutions:
Eyeglasses: Corrective lenses in eyeglasses are often the first line of defense against astigmatism. Lenses for astigmatism are designed to counteract the irregular curvature of the eye, providing clearer, sharper vision.
Contact Lenses: For some, contact lenses are preferable to glasses. Toric lenses, which are specially designed to fit the shape of an astigmatic cornea, are often effective. There are also rigid gas-permeable (RGP) or hybrid lenses that can provide a more stable correction, particularly for high degrees of astigmatism.
Refractive Surgery: Laser procedures like LASIK or PRK can reshape the cornea and correct mild to moderate astigmatism. Surgery is typically recommended for those who prefer a more permanent correction and meet certain criteria.
Orthokeratology (Ortho-K): This non-surgical option involves wearing specially designed, rigid contact lenses overnight to temporarily reshape the cornea. This approach can offer clear vision throughout the day without the need for glasses or contacts, though the effect is temporary and requires nightly wear.
Regular Eye Exams: Even if astigmatism is mild, maintaining regular eye exams helps keep your prescription updated and your vision as clear as possible. Routine exams can also help catch changes in vision early, making it easier to manage your eyesight comfortably.
Astigmatism is a common, manageable vision issue that doesn’t have to interfere with your quality of life. With solutions ranging from eyeglasses and contact lenses to surgical options, you can choose a method that aligns with your lifestyle and vision goals. Remember, regular eye exams are key to keeping your vision in check and addressing astigmatism or other vision changes as they occur. If you’re experiencing symptoms of astigmatism or have noticed recent vision changes, consult with an eye care professional to explore your options for clearer sight.