- Posted on: Aug 15 2018
People usually understand what it means to be nearsighted, myopia. You can see well up close, but distance vision isn’t perfect. To be more clinical, your distance vision has a refractive error.
The opposite is farsightedness, hyperopia. You can see well at distance, but up close has a refractive error and needs correction.
It’s the third common vision problem that most people don’t quite understand — astigmatism. Even the name is incorrectly used, as many people say they have “a stigmatism.”
At The Eye Clinic, we see astigmatism every day in our patients. Actually, just about all of us have some degree of astigmatism in our vision. We have various options for correcting astigmatism and giving you clearer vision.
Here’s some information so you understand just what astigmatism means for your vision.
What is astigmatism?
Astigmatism is a very common imperfection with the eye’s ability to accurately focus light. In most cases, the cause of a person’s astigmatism is that the cornea, the clear round dome covering the eye’s iris and pupil, is imperfectly shaped. Normally, the cornea is round like a baseball. But if you have astigmatism, your cornea is shaped more oblong like a football. This oblong shape affects how light rays are refracted into the eye, making objects at various distances appear blurred. Light is focused on several different points within the eye, rather than forming a single, clear focus point on the retina. Astigmatism is different than myopia or hyperopia in that it focuses light on several different points, rather than just the single refractive error.
Why does astigmatism occur?
Most people with astigmatism are born with the condition. It’s thought that most people have some degree of astigmatism, although most don’t require correction. It is most likely an inherited condition.
You can develop astigmatism after having an eye disease, eye injury, or eye surgery.
Contrary to your grandmother’s warnings, you cannot develop astigmatism from reading in low light or from sitting very close to the television.
How does The Eye Clinic correct for astigmatism?
Although the correction is handled a little differently than with nearsightedness or farsightedness, astigmatism can be corrected with the same tools: eyeglasses, contact lenses, or refractive surgery.
- Eyeglassesare made with lenses that help compensate for the uneven shape of your eye. While correcting for astigmatism, they can also correct myopia or hyperopia.
- Contact lensesuse what are called “toric” lenses to correct astigmatism. This type of lens is relatively new. Each lens has a tiny vertical line on it toward the edge of the lens. When the patient puts the lens in his or her eye, the line needs to be oriented to the top of your eye. This type of lens doesn’t rotate like a regular contact, but it stays oriented in that way to correct for the shape of your cornea.
- Refractive surgeryuses a laser to reshape the curves of your cornea. Usually, after the laser has corrected for either myopia or hyperopia, it is then used to create slits in the cornea, called corneal relaxing incisions. These allow the cornea to attain a more normal round shape, correcting for astigmatism.
Now you know — you don’t have “a stigmatism.” But if you have trouble focusing at different distances, you probably do have “astigmatism.” Come see the team at The Eye Clinic and we’ll fix your vision. Call us at (503) 297-4718 or (503) 228-6681 to make an appointment.
Posted in: Astigmatism