Astigmatism is a common refractive error that affects how the eye focuses light, leading to blurred or distorted vision at all distances. It occurs when there is an imperfect curvature of the cornea or lens, which causes light to focus unequally on the retina.
What Are the Most Common Symptoms of Astigmatism?
- Blurry vision
- Eye discomfort
- Trouble seeing clearly at night
What Causes Astigmatism?
- Eye injury
- Ageing
- Inherited or congenital causes
- A complication following eye surgery
- Other eye conditions such as keratoconus
Diagnosing Astigmatism
- Eye Chart: This is measured by reading letters on a distance chart. It is expressed as a fraction (e.g. 20/40), where the top number is the standardized testing distance (20 feet) and the bottom number is the smallest letter size read.
- Keratometry: This is a method to measure the curvature of the cornea. It involves focusing a light circle on the cornea and measuring its reflection to determine the cornea’s curvature. Corneal topography, gaining popularity, generates a detailed contour map of the cornea, offering more insights into its shape.
- Phoropter: A phoropter is a diagnostic device used to measure refractive errors in the eyes, such as astigmatism, by allowing precise adjustments of lenses to find the optimal prescription for an individual’s vision correction.
Treatment Options for Astigmatism
- Eyeglasses: People often choose eyeglasses containing a cylindrical lens prescription, which compensates for astigmatism by providing additional power in specific parts of the lens.
- Contact Lenses: It provides clearer vision and require regular cleaning and care. There are many different types of contact lenses and your optician or ophthalmologist will be able to advise you on the best option for your case.
- Laser and Other Refractive Surgery Procedures: Refractive surgery procedures for treating astigmatism, such as LASIK, involve reshaping the cornea to correct the irregular curvature causing blurred vision. Using laser technology, these surgeries precisely modify the corneal surface, aiming to reduce or eliminate astigmatism and improve overall visual acuity without the need for glasses or contact lenses.