Astigmatism
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.
Can astigmatism be cured?
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.
Can astigmatism get worse?
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.
Astigmatism vs normal vision
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.
