ASTIGMATISM

Understanding Astigmatism: Causes, Symptoms, and Treatment

Astigmatism is a common refractive error in the eye, meaning that it affects how light is focused onto the retina. It results from an irregular shape of the cornea or lens, which prevents light from being properly focused. This leads to blurred or distorted vision. Astigmatism is often present from birth and can affect both nearsighted and farsighted individuals.

Causes of Astigmatism

Astigmatism typically arises due to an abnormal shape of the cornea, the transparent front surface of the eye, or the lens, the clear structure inside the eye that helps focus light. In a normal eye, the cornea and lens are smoothly curved, like a basketball. However, in an eye with astigmatism, the cornea or lens may be shaped more like a football, with one meridian being steeper than the other. This uneven curvature causes light to be refracted at different angles, leading to distorted or blurred vision.

While the exact cause of astigmatism is not always clear, it is believed to be largely hereditary. In some cases, astigmatism may result from an injury or surgery to the eye, or it could develop after certain eye conditions, such as keratoconus.

Symptoms of Astigmatism

The signs of astigmatism can vary depending on its severity, but common symptoms include:
•         Blurred or distorted vision: This is the hallmark symptom of astigmatism, which may be noticed when reading, driving, or looking at objects both up close and far away.
•         Eye strain or discomfort: Due to the eye’s efforts to compensate for the irregular curvature, individuals with astigmatism may experience fatigue or strain, especially after prolonged visual tasks.
•         Headaches: As the eyes work harder to focus, tension may build, leading to frequent headaches.
•         Squinting: People with astigmatism often squint in an attempt to focus more clearly, which can worsen eye strain.
•         Double vision: In severe cases, astigmatism can cause double vision, particularly when reading or looking at fine details.

Diagnosing Astigmatism

An optometrist or ophthalmologist can diagnose astigmatism through a routine eye exam. This typically includes:
•         Visual acuity test: The eye care professional will test how clearly you can see letters or images at different distances.
•         Keratometry or corneal topography: These tests measure the curvature of the cornea to determine the degree of astigmatism.
•         Refraction test: This test helps determine the correct prescription for glasses or contact lenses by evaluating how light is focused on the retina.

Treatment Options for Astigmatism

Astigmatism is usually treatable with corrective lenses or surgical options. The most common treatments include:
    1.     Glasses: Eyeglasses with a cylindrical lens prescription can help compensate for the irregular curvature of the cornea or lens, providing clearer vision.
    2.     Contact lenses: Special toric contact lenses are designed to correct astigmatism by matching the curvature of the cornea. For some people, rigid gas-permeable contacts may be recommended to provide clearer vision.
    3.     Refractive surgery: In some cases, surgical procedures such as LASIK or PRK can reshape the cornea to correct astigmatism and reduce or eliminate the need for glasses or contacts. These surgeries are typically recommended for people with stable vision who are over the age of 18.

Living with Astigmatism

Astigmatism is a manageable condition, and with appropriate treatment, most people can enjoy normal or near-normal vision. It is important for individuals with astigmatism to have regular eye exams to monitor any changes in their vision and ensure their prescription is up to date. Additionally, people with more severe astigmatism may find it helpful to wear specialized contact lenses or undergo corrective surgery for long-term improvement.

Conclusion

Astigmatism is a common, treatable eye condition that can significantly affect vision if left uncorrected. With early diagnosis and appropriate corrective measures, individuals with astigmatism can enjoy clear, comfortable vision. If you notice symptoms like blurred or distorted vision, it’s a good idea to schedule an eye exam to determine if astigmatism is the cause.