Astigmatism: the eye’s shape causes blurred or distorted vision at all distances

Astigmatism is a common vision condition where the eye’s shape causes blurred or distorted vision at all distances. While it often occurs with other refractive errors like myopia (nearsightedness) or hyperopia (farsightedness), astigmatism can also appear on its own. Here’s a closer look at its causes, symptoms, and treatment options.

What Causes Astigmatism?

Astigmatism occurs when the cornea (the clear front surface of the eye) or the lens inside the eye is irregularly shaped. Instead of being perfectly round like a basketball, the cornea or lens is shaped more like a rugby ball, with two different curvatures. This irregular shape causes light entering the eye to focus unevenly on the retina, leading to blurred or distorted vision. Causes include:

• Genetics – Astigmatism often runs in families and is usually present from birth.

• Eye Injury or Surgery – Scarring on the cornea from an injury or eye surgery can cause astigmatism.

• Keratoconus – A rare condition where the cornea gradually becomes thin and cone-shaped, leading to progressive astigmatism.

Symptoms

• Blurred or distorted vision at any distance

• Eye strain and headaches, especially after reading or screen time

• Difficulty with night vision

• Squinting to see more clearly

If you experience any of these symptoms, an eye exam can confirm whether astigmatism is the cause.

Diagnosis

Astigmatism is diagnosed during a comprehensive eye exam, including:

• Visual Acuity Test – To measure clarity of vision at different distances.

• Keratometry – To measure the curvature of the cornea.

• Refraction Test – To determine the proper prescription for glasses or contact lenses.

Treatment Options

There are several effective options for correcting astigmatism:

• Eyeglasses – Most people with astigmatism can achieve clear vision with specially prescribed lenses.

• Contact Lenses – Toric lenses are designed specifically for astigmatism, correcting the uneven curvature of the eye.

• Orthokeratology (Ortho-K) – Rigid contact lenses worn overnight to temporarily reshape the cornea, providing clear daytime vision without glasses or contacts.

• Refractive Surgery – LASIK or other laser surgeries reshape the cornea to correct mild to moderate astigmatism, offering a permanent solution for adults with stable prescriptions.

Managing Astigmatism for Better Vision

Regular eye exams are essential, as astigmatism can change over time. For those with mild astigmatism, good lighting, taking breaks from screen time, and wearing appropriate corrective lenses can make a significant difference in daily comfort.

Astigmatism is a manageable condition that can be effectively treated with glasses, contacts, or surgery. If you experience blurred vision or eye strain, consult an eye care professional to discuss your options for clear, comfortable vision.