Astigmatism

Astigmatism is a common vision condition that affects the way light enters the eye, resulting in blurred or distorted vision. It occurs when the cornea (the clear front surface of the eye) or the lens inside the eye has an irregular shape. Normally, the cornea and lens are smooth and evenly curved, allowing light to focus properly on the retina at the back of the eye. However, in astigmatism, the cornea or lens may have a more oval or football-shaped curvature, causing light to focus unevenly on the retina.

Types of astigmatism:

1. Corneal astigmatism: This is the most common type of astigmatism and occurs when the cornea has an irregular shape. It may be shaped more like a football than a round basketball. Corneal astigmatism can be further classified as regular or irregular, depending on the pattern of corneal curvature.

2. Lenticular astigmatism: This type of astigmatism is caused by an irregularity in the shape of the lens inside the eye. It may occur in addition to or independent of corneal astigmatism.

Symptoms of astigmatism:

1. Blurred vision

Blurry vision is one of the primary symptoms of astigmatism. The irregular shape of the cornea or lens causes light to focus unevenly on the retina, resulting in blurred images at all distances. It can affect both close-up and distant objects.

2. Eye strain

Astigmatism often leads to eye strain and discomfort. The constant effort required to focus and interpret blurred images can cause fatigue and eye strain. It may further lead to headaches and overall discomfort.

3. Headaches

The eye strain caused by astigmatism can trigger recurrent headaches. The continuous effort of the eyes to compensate for the blurred vision can strain the surrounding muscles, leading to tension headaches.

4. Squinting

Squinting is a common instinctive response to astigmatism. By partially closing their eyes, individuals with astigmatism attempt to temporarily correct the corneal irregularity, hoping to improve the focus of light entering their eyes.

Astigmatism vs normal vision

To better understand astigmatism, it is essential to know how normal vision works:

1. Understanding normal vision

Normal vision is characterized by the ability to focus on objects at different distances clearly. The cornea and lens work together to refract light and direct it to the retina, creating a sharp and well-defined image.

2. How astigmatism affects vision

In astigmatism, the irregular shape of the cornea or lens disrupts the normal refraction process. This results in different focal points for different meridians of the eye, causing distorted or blurred vision. The severity of astigmatism determines the extent of visual impairment.

3. Diagnosing astigmatism

Astigmatism can be diagnosed during a comprehensive eye examination conducted by an eye care professional. The examination may include visual acuity tests, refraction tests, and corneal topography to determine the presence and severity of astigmatism.

If you experience any of the symptoms mentioned above or suspect you might have astigmatism, it is crucial to schedule an appointment with an optometrist or ophthalmologist. They can accurately diagnose your condition and recommend appropriate corrective measures, such as prescription glasses or contact lenses. Regular eye examinations can help detect astigmatism early and ensure optimal eye health.