Astigmatism is a common vision condition that affects how light enters the eye, leading to 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. Unlike a perfectly round cornea, an eye with astigmatism has an oval or football-like shape, which causes light to focus unevenly on the retina. This refractive error can occur on its own or along with other vision problems such as nearsightedness (myopia) or farsightedness (hyperopia).
In this article, we will explore the causes, symptoms, diagnosis, and treatment options for astigmatism.
1. Causes of Astigmatism
Astigmatism is primarily caused by an irregularly shaped cornea or lens. A normal eye has a round, symmetrical cornea that bends light evenly onto the retina, producing a clear image. However, in astigmatism, the cornea is more curved in one General direction than the other, leading to improper light focus and blurred vision.
Common causes include:
✅ Genetics – Astigmatism often runs in families and can be present at birth (congenital astigmatism).
✅ Eye injuries – Trauma or surgery that affects the cornea can cause astigmatism.
✅ Keratoconus – A rare eye condition that causes the cornea to become thinner and cone-shaped, leading to severe astigmatism.
✅ Incorrect pressure on the eyelids – Some research suggests that prolonged pressure on the cornea from eyelids or frequent eye rubbing can contribute to astigmatism.
2. Symptoms of Astigmatism
The symptoms of astigmatism vary depending on the severity of the condition. Some individuals with mild astigmatism may not notice any symptoms, while others may experience:
Blurry or distorted vision – Objects may appear stretched or wavy at all distances.
Eye strain and discomfort – Extended periods of reading or screen use may cause tired eyes.
Headaches – Struggling to focus on objects can lead to frequent headaches.
Difficulty seeing at night – Poor night vision and halos around lights are common complaints.
Frequent squinting – People with astigmatism may squint to try to improve focus, leading to eye fatigue.
3. How is Astigmatism Diagnosed?
Astigmatism is diagnosed through a comprehensive eye exam performed by an optometrist or ophthalmologist. Tests that help detect astigmatism include:
Visual Acuity Test – The standard eye chart test to assess how well you can see at different distances.
Keratometry – Measures the curvature of the cornea to determine the degree of astigmatism.
Refraction Test – Determines the correct prescription for glasses or contact lenses.
If astigmatism is detected, your eye doctor will discuss the best treatment options based on its severity.
4. Treatment Options for Astigmatism
There are several ways to correct astigmatism, depending on the level of vision impairment.
Eyeglasses and Contact Lenses
Prescription glasses – The simplest and most common way to correct astigmatism.
️ Toric contact lenses – Specially designed lenses that adjust for the uneven curvature of the eye.
Refractive Surgery
For those who want a long-term solution, surgical options include:
LASIK (Laser-Assisted In Situ Keratomileusis) – A laser reshapes the cornea for better focus.
PRK (Photorefractive Keratectomy) – A laser removes a small layer of cornea tissue to correct the shape.
Orthokeratology (Ortho-K)
This involves wearing special rigid contact lenses overnight to temporarily reshape the cornea, providing clear vision during the day without the need for glasses or lenses.
Astigmatism is a common and treatable vision condition caused by an irregularly shaped cornea or lens. While it can lead to blurred vision, eye strain, and headaches, various treatments such as glasses, contact lenses, and laser surgery can help correct it. If you experience any symptoms of astigmatism, scheduling a routine eye exam can help ensure you receive the right diagnosis and treatment for clearer vision.