Astigmatism is a vision condition that affects both near and distant vision. It occurs when the cornea — the clear, dome-shaped front surface of the eye — is shaped differently from one side to another. This irregular shape causes light entering your eye to focus incorrectly on your retina, resulting in blurred vision.
Astigmatism often occurs together with nearsightedness or farsightedness. As a result, it becomes difficult to see clearly at all distances. In the US, approximately 33% of people have astigmatism. This condition usually develops during childhood, but some people are born with it.
If you have astigmatism, you may notice that straight lines appear wavy or distorted when you look at them. Or perhaps your vision seems blurry no matter how hard you try to focus on objects close up or far away. Although astigmatism is not life-threatening, it can affect your eyesight and quality of life.
In this article, we'll look at astigmatism's causes and symptoms and ways to treat and manage it.
The curvature of your cornea causes astigmatism. Generally, this cornea is shaped like a football (or oval) and helps focus light onto your retina, which sends images to your brain. If you have astigmatism, the shape of your cornea — the transparent covering over the iris and pupil — isn't round and smooth like it should be. Instead, it's more like a rugby ball or oblong shape with curves on both sides. This causes problems when light passes through your eye, as it can't focus properly. Instead of focusing on a single point on your retina, the light rays are scattered across multiple points and create blurry images.
Astigmatism is diagnosed when you have an eye exam as a child or teen. However, it can develop later in life, too. If you already have astigmatism and suddenly notice changes in your vision, contact your doctor immediately.
You can get an eye exam to diagnose astigmatism. Your eye doctor will use an autorefractor tool to measure your refractive error and determine whether you have astigmatism. This device looks like a small TV screen that projects images of letters, numbers, and other objects onto your retina.
As you look at the images, your doctor will ask you to focus on them and tell them when they appear clear. As you do this, the autorefractor measures how much effort your eyes need to bring each image into focus. If astigmatism is present, both eyes will require different attempts to see clearly. It then uses this information to calculate whether you need glasses or contacts for clear vision.
If you have astigmatism, there are several treatment options available. Your doctor will discuss these with you based on your symptoms and how your condition causes much vision impairment.
Contact lenses are the most common treatment for astigmatism. They can correct both horizontal and vertical misalignment of the cornea, making it easier to see clearly. Several types of contact lenses available can help reduce symptoms associated with astigmatism:
- Soft toric contacts use flexible materials to gently reshape your eye's cornea so it becomes more spherical. This helps correct any distortion caused by astigmatism.
- Gas-permeable contacts are rigid lenses that a specialist must fit. They can correct astigmatism but may not suit those with poor vision.
- Hybrid contact lenses are a combination of soft and gas-permeable lenses. They're made from a flexible material that's easy to wear but have an added layer of rigid gas-permeable material at the front so they can correct astigmatism.
Glasses are another option for people with astigmatism. They work by bending light to focus on the retina so you can see clearly. Like contact lenses, glasses aren't suitable for everyone and may take some getting used to. However, you can remove them anytime if they cause discomfort, so they're a good choice if you frequently find yourself unable to wear your contact lenses.
If your astigmatism is severe, it may be possible to correct it with surgery. This can include reshaping the cornea or removing some of its tissue, making it flatter and more able to focus light.
The procedure is only suitable for people with a certain degree of astigmatism, so ask your optometrist if it's an option. The decision to have surgery is big, so it's essential to understand what it involves and the potential risks. Surgery isn't always successful, and there's no guarantee that you won't need glasses after it.
Astigmatism is a common eye condition that affects millions of people. It is not a severe condition, but it can make focusing on objects complex and cause eye strain. It might make you experience headaches, eyestrain, blurred vision, and difficulty driving at night.
There are many ways to manage astigmatism, including wearing glasses or contact lenses and following an eye care plan. Surgery is a last resort, but it can effectively treat more severe cases of astigmatism.
If you're diagnosed with astigmatism, you must understand your options. Contact CV Optometry today to talk to an optometrist about the best treatment for you and your vision.