Astigmatism is a common vision condition that causes blurred or distorted vision due to an irregular shape of the cornea or sometimes the curvature of the lens inside the eye, which may require those suffering from it to get spectacles or contact lenses in Sri Lanka. In a normal eye, the cornea and lens are evenly curved in all directions, helping to focus light rays sharply onto the retina at the back of the eye.


However, in astigmatism, the cornea or lens is curved more steeply in one direction than in another, which causes light rays to focus unevenly, resulting in blurred vision at all distances. This condition can occur alongside near-sightedness (myopia) or farsightedness (hyperopia).


According to opticians in Sri Lanka, astigmatism occurs when the cornea or lens of the eye is irregularly shaped, which affects how light is refracted and focused onto the retina. There are two main types of astigmatism:

  • Corneal astigmatism: This is the most common type and occurs when the cornea (the transparent front surface of the eye) has an irregular curvature. Instead of being perfectly round like a basketball, a cornea with astigmatism is shaped more like a football, with one meridian being steeper or more curved than the meridian perpendicular to it.
  • Lenticular astigmatism: This type of astigmatism occurs due to an irregularity in the shape of the lens inside the eye.


Causes of Astigmatism

  • Genetics: Astigmatism can be inherited and tends to be present from birth.
  • Eye injury: Scarring or thinning of the cornea caused by injury or surgery can lead to astigmatism.
  • Keratoconus: This is a condition where the cornea progressively thins and bulges outward, causing astigmatism.
  • Changes in the shape of the lens: This can occur with ageing or certain medical conditions.


Symptoms of Astigmatism

  • Blurred vision: Objects at any distance may appear blurred or distorted.
  • Eyestrain: Trying to focus on objects for long periods can cause discomfort or fatigue.
  • Headaches: Especially after prolonged use of the eyes, such as reading or using a computer.
  • Difficulty with night vision: Objects may appear blurrier or ghosted in low light conditions.


It is important to note that many people have some degree of astigmatism, and mild cases may not require correction. However, if astigmatism affects vision significantly, it can be corrected with eyeglasses, contact lenses, or refractive surgery. Regular eye testing in Sri Lanka is crucial for diagnosing and managing astigmatism to ensure optimal vision health.


Treatment options for astigmatism

Astigmatism can typically be corrected or managed effectively through experienced professionals in eye care in Sri Lanka, depending on the severity and type of astigmatism. Here are the common treatment options:

  • Prescription Eyeglasses: This is the most common and straightforward treatment for astigmatism. Eyeglasses with lenses that have a special cylindrical power can compensate for the uneven curvature of the cornea or lens, correcting blurred vision.
  • Contact Lenses: Special toric soft contact lenses are designed to correct astigmatism. These lenses have different powers in different meridians of the lens to address the irregular shape of the cornea or lens. Rigid gas permeable (RGP) lenses can also correct astigmatism by maintaining a smooth surface over the irregular cornea.
  • Orthokeratology (Ortho-K): This is a non-surgical treatment where specially designed gas permeable contact lenses are worn overnight to reshape the cornea temporarily. In the morning, the lenses are removed, and the reshaped cornea provides clear vision throughout the day without the need for glasses or contacts.
  • Refractive Surgery: For those who want a more permanent solution, refractive surgeries such as LASIK (Laser-Assisted in Situ Keratomileusis) or PRK (Photorefractive Keratectomy) can be considered. These surgeries use laser technology to reshape the cornea, correcting refractive errors including astigmatism. Customised laser treatments, such as wavefront-guided LASIK or PRK, can address even complex forms of astigmatism.
  • Astigmatic Keratotomy: This is a surgical procedure where the surgeon makes precise incisions in the cornea to change its shape and correct astigmatism. This procedure is less common now due to the advent of more advanced laser surgeries.
  • Prescription Glasses for Specific Tasks: In some cases, especially for mild astigmatism, glasses may only be needed for specific tasks that require sharp vision, such as driving or reading.


Treatment choice depends on various factors including the severity of astigmatism, lifestyle preferences, overall eye health, and the recommendation of an eye care professional. Regular eye exams are essential to monitor astigmatism and ensure the chosen treatment continues to provide optimal vision correction.

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