What is astigmatism?
Astigmatism is a refractive error in which the cornea or lens does not have a perfectly curved shape. The eye is not able to focus light evenly onto the retina, causing blurred vision. While a normal cornea is curved evenly, like a basketball, a cornea with astigmatism is curved irregularly, as a rugby ball, and requires a different level of vision correction. Astigmatism can occur in people of any age. Contact lenses to correct astigmatism require two additional powers, called the cylinder and axis.
If left untreated, astigmatism can cause headaches, eye strain and fatigue, especially after long periods of reading or working on a computer.
Yes. There are two types of
astigmatism, and each can be treated differently.
Regular astigmatism is where the cornea is curved more in one direction than the other. It's more common than irregular astigmatism and can be corrected with glasses or toric contact lenses. Irregular astigmatism is an irregular curvature of the cornea and is often the result of an eye injury that causes a scar to develop on the cornea. It cannot be corrected with glasses, but can sometimes be corrected with rigid contact lenses.
For adults, there’s also an option to correct astigmatism permanently with laser surgery.
If you’re asking “Could my astigmatism be getting worse?”, unfortunately it’s true. Our vision can start to deteriorate with age, so it’s important to get regular eye exams and keep your prescription up to date.
In this picture, you can see how the visual error of astigmatism works. If the cornea is misshapen, then light rays don’t collide at the same point on the retina, and images appear blurry. You can also see the blurred vision associated with astigmatism compared with the clear vision of a normal eye.