Astigmatism is a common vision condition where the eye's cornea or lens has an irregular curvature, causing blurred vision at both near and far distances.
Understanding Astigmatism
Astigmatism isn't a disease; it's a refractive error, meaning the eye doesn't focus light evenly onto the retina. Ideally, the cornea and lens are smoothly curved like a baseball. In astigmatism, one or both of these elements are shaped more like a football. This irregular shape prevents light from focusing properly on the retina, resulting in blurry or distorted vision.
Causes of Astigmatism
Astigmatism is often present at birth and can occur in combination with other refractive errors like nearsightedness (myopia) or farsightedness (hyperopia). While the exact causes are not fully understood, genetics often play a role. In some cases, astigmatism can develop after an eye injury, eye disease, or surgery.
Symptoms of Astigmatism
Common symptoms include:
- Blurred or distorted vision at all distances.
- Eyestrain.
- Headaches.
- Squinting.
- Difficulty seeing at night.
Diagnosis and Treatment
An eye exam can easily diagnose astigmatism. Treatment options include:
- Corrective Lenses: Glasses or contact lenses can compensate for the irregular curvature and improve vision.
- Refractive Surgery: Procedures like LASIK or PRK can reshape the cornea to correct the astigmatism.
Types of Astigmatism
Astigmatism can be classified in different ways:
- Corneal Astigmatism: Caused by irregularities in the cornea.
- Lenticular Astigmatism: Caused by irregularities in the lens.
- Regular Astigmatism: The principal meridians (the steepest and flattest curves) are 90 degrees apart. This is the most common type and is usually corrected easily with glasses or contacts.
- Irregular Astigmatism: The principal meridians are not 90 degrees apart. This can be caused by corneal scarring or certain eye diseases and can be more challenging to correct.
Astigmatism is a common and treatable vision problem that results from an irregularly shaped cornea or lens, causing blurry or distorted vision. Corrective lenses or refractive surgery can effectively improve vision.
