Astigmatism is a common refractive error that occurs when the cornea or the lens of the eye has an irregular shape, leading to distorted or blurred vision. Unlike nearsightedness (myopia) or farsightedness (hyperopia), where the eye’s shape is more spherical, astigmatism is characterized by an oval or football-shaped curvature of the cornea or lens. This irregularity causes light entering the eye to focus on more than one point on the retina, resulting in distorted images at various distances.
Most people who have astigmatism have symptoms of ghosting or doubling of images. In extreme cases, images both close-up and in the distance appear blurred. Many people who have nearsightedness (myopia) or farsightedness (hyperopia) also have astigmatism.
How do I know if I have astigmatism?
Astigmatism usually is combined with nearsightedness or farsightedness. If you wear glasses or contacts for all distances, you may have astigmatism. It is best diagnosed by your eye doctor during your annual eye exam.
What causes astigmatism?
Astigmatism is a genetic condition that typically increases through your teens, but usually stabilizes in your twenties or thirties. There are several factors that can contribute to its development:
- Corneal Shape: Most cases of astigmatism are related to irregularities in the shape of the cornea, the clear front surface of the eye. Instead of being perfectly curved, the cornea may have a more oblong shape, which can cause light to scatter and create blurred vision.
- Lens Shape: In some cases, astigmatism may be caused by irregularities in the shape of the eye’s crystalline lens, which is located just behind the iris. Changes in the lens shape can also lead to astigmatism.
- Genetics: Astigmatism often has a genetic component. If your parents or other close relatives have astigmatism, you may be at a higher risk of developing it.
- Eye Injuries: Trauma to the eye, such as injuries that affect the shape of the cornea or lens, can lead to astigmatism.
- Eye Conditions: Certain eye conditions, such as keratoconus (a progressive thinning and bulging of the cornea) or scarring of the cornea due to infection or injury, can cause irregular corneal shape and astigmatism.
- Changes with Age: Some individuals may develop astigmatism as they age, especially if their corneas or lenses change shape over time.
Can astigmatism be fixed?
Astigmatism can be effectively corrected through various methods, depending on the severity of the condition and individual preferences. Here are common ways to address astigmatism:
- Prescription Glasses:
– Eyeglasses with cylindrical lenses are the most common and non-invasive way to correct astigmatism. These lenses have different powers in different meridians to counteract the irregular shape of the cornea or lens. - Contact Lenses:
– Toric contact lenses are specifically designed to correct astigmatism. They provide a stable position on the eye to ensure the correction aligns with the irregular curvature. - Refractive Surgery:
– Laser vision correction surgeries, such as LASIK eye surgery or PRK (Photorefractive Keratectomy), can reshape the cornea to correct astigmatism. These surgeries are suitable for many individuals with astigmatism, but candidacy depends on factors like the degree of astigmatism and overall eye health. - Toric Intraocular Lenses (IOLs):
– For individuals undergoing cataract surgery or refractive lens exchange, toric IOLs can be implanted to correct astigmatism. These specialized lenses address both the cataract and the astigmatism simultaneously. - Orthokeratology (Ortho-K):
– Ortho-K involves wearing specially designed gas-permeable contact lenses overnight. These lenses temporarily reshape the cornea, providing clear vision during the day. Ortho-K is often used for mild to moderate astigmatism. - Combination Correction:
– In some cases, a combination of approaches may be used, such as using glasses for certain activities and contact lenses for others.
It’s important to note that astigmatism is a common vision problem and can often be corrected with eyeglasses, contact lenses, or refractive surgery, such as LASIK or PRK. An eye exam by an Eye Associates of South Texas optometrist or ophthalmologist can diagnose astigmatism and determine the degree and type of astigmatism you have. If you experience blurred or distorted vision, call us at (830) 379-3937 for an accurate diagnosis and appropriate treatment options. Source: nvisioncenters.com.
