A nasty sounding word, isn’t it? Astigmatism is the leading refractive cause for needing glasses. The eye is an optical system. A perfectly spherical eye has no astigmatism, but most people do have some amount. A small amount of astigmatism can create some night driving and far vision blur. What is it? Consider a perfectly spherical crystal-clear ball: an image passing through would create a single focal point in your eye. If a baseball slugger whacked that ball out of the park, that ball might become a little warped which would create a second image, or a distortion like a carnival mirror creates — a second focal point in your eye — and we need only one for clear vision. So, there is a “warping” of the optics of the eye of a certain amount and at a certain angle. The greater the astigmatism, the greater our vision is distorted at all distances. So, too, is close reading.
What is astigmatism?
Your cornea is a clear, round dome that covers the iris and pupil of your eye. A normal, healthy cornea is smooth and curves equally in all directions, allowing light to focus properly onto the retina at the back of your eye, allowing you to see clearly.
When your cornea doesn’t curve evenly in all directions, its irregular shape causes light to refract incorrectly, distorting your vision. A misshapen cornea is called corneal astigmatism.
Astigmatism can also occur in the lens of your eye, just behind your cornea. If you’re diagnosed with a lenticular astigmatism, it means you have a misshapen lens.
What are the symptoms of astigmatism?
No matter what type of astigmatism you have — corneal or lenticular — it may cause objects both near and far to appear blurry and distorted. If your astigmatism is very mild, you may not experience any significant vision problems.
If your astigmatism is moderate or severe, however, you may experience:
- Chronic headaches
- Eyestrain and squinting
- Poor night vision
Because astigmatism is usually inherited, most people who have the problem were actually born with it. Astigmatism can also develop following an eye trauma, disease, or surgery.
How is astigmatism corrected?
Having astigmatism may make your prescription a bit more complicated, but it won’t prevent you from getting the type of corrective lens that best fits your life. In fact, most forms of astigmatism are easily corrected.
Many people opt for eyeglasses, which are made with a special cylindrical lens prescription that offsets astigmatism. Children, teens and young adults who choose glasses to correct astigmatism typically need only a single-vision lens that provides clear vision at all distances. Adults over 40 are more likely to require a bifocal or progressive vision lens.
Contact lenses are also an excellent corrective option for those with a moderate amount of astigmatism; in fact, some people will have better vision with contact lenses rather than eyeglasses. Contact lenses also provide an unobstructed, wider range of view than glasses.
What are toric contact lenses?
Toric contact lenses are often the best choice for contact lens wearers who have astigmatism because they have a special shape that’s specifically designed to address the problem. Toric contact lenses create different refractive, or focusing, powers that can help correct any type of astigmatism.
Toric contacts typically have a thicker zone at the bottom that keeps them from rotating when they’re in place. This built-in feature also helps you orient the lenses the same way every time, giving you reliably consistent visual acuity.
Toric lenses are available as soft or hard lenses, and come in every wear schedule, ranging from dailies to disposables and more. If you need contact lenses to help correct astigmatism, Dr. Ales can help you choose the toric lens that best fits your lifestyle.
To learn more about all the corrective options available for astigmatism, call Optik Birmingham or schedule an appointment online today.