Astigmatism is one of the most common reasons people need glasses. Despite the unfamiliar name, it is simply a focusing error, like short or long sight.
What causes it
A perfectly round cornea focuses light to a single point. In astigmatism, the cornea or the lens inside the eye is curved more in one direction than the other. Light focuses at two different points, so images look blurred or stretched. Most people are born with some astigmatism, and it can change slowly over time.
Symptoms
- Blurred or distorted vision, both near and far
- Eye strain and headaches, especially after reading or screen work
- Squinting to see clearly
- Difficulty driving at night, with glare around lights
How it is corrected
- Glasses with a cylindrical correction
- Toric contact lenses, designed to stay in the right position
- Laser refractive surgery to reshape the cornea, for suitable adults
- Toric lens implants during cataract surgery
When astigmatism keeps increasing
Astigmatism that changes quickly, especially in teenagers and young adults, can be a sign of keratoconus, a condition where the cornea thins and bulges. Read our keratoconus guide and avoid rubbing your eyes.
Frequently asked questions
Is astigmatism serious?
Usually not. It is a common focusing error that is easily corrected. Rapidly increasing astigmatism should be checked for keratoconus.
Can children have astigmatism?
Yes. Uncorrected astigmatism in children can lead to lazy eye, so regular eye tests are important.
Sources
This article is for general information and does not replace an examination by an eye doctor. If you have symptoms, please book a consultation.