All About Astigmatism - Symptoms, Causes and Treatment

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Astigmatism Guide

Astigmatism is one of a group of eye conditions, called refractive errors, that cause a disturbance in the way light rays are focused within the eye. This occurs when the cornea, a thin sheet of clear tissue covering the eye around the pupil, is irregularly curved. Normally, the eye is a near-perfect sphere, but in astigmatism, the front surface of the cornea is curved more in one direction than in the other--more football-shaped than basketball-shaped. In fact, most astigmatic corneas have two axes of irregular curvature, one flatter than the other. This distortion causes an inability of the eye to focus light rays correctly onto the retina and may result in vision resembling the distortion in a funhouse mirror. This blurred vision applies to objects at all distances, though the condition may be accompanied by near- or far-sightedness. Unequal astigmatism may ultimately lead to amblyopia, or "lazy eye," a condition in which one eye suffers loss of acuity due to the patient favoring his or her other, less astigmatic, eye.

Astigmatism can be Mild or Serious

Not all people with astigmatism require medical assistance; the distortion can be fairly mild. Some experts believe all human beings have a degree of astigmatism. However, in many cases the curvature of the eye is more severe, and corrective lenses must be used to refocus light rays in the eye. These corrective aids may take the form of spectacles or contact lenses. Many astigmatic patients use specially curved contact lenses called toric lenses, which include an additional power element called a cylinder. These lenses bend incoming light farther in one direction than in another in order to oppose the refractive effects of eye curvature. Astigmatism may also be corrected by a refractive surgical procedure called laser-assisted in-situ keratomileusis, or lasik for short. Radio keratotomy and astigmatic keratotomy are two older forms of corrective corneal surgery.

Symptoms

Symptoms of astigmatism include blurring or distortion of images at all distances, plus headache, fatigue, eye irritation, and frequent squinting. These symptoms may grow more intense as a person gets older, so it's a good idea to get regular eye check-ups, especially if a person has already been fitted for corrective lenses. The patient's prescription may need to be altered in order to correct for changes in eye curvature.

Diagnosis

Many eye care clinics and contact suppliers have tests for astigmatism posted on their websites. The most common test is a radial design with lines arranged in angles from zero to 180 degrees, similar to that associated with the sun as it rises above the horizon. Other test designs include a specially printed eye chart and square shapes made of a series of lines.

For each of these tests, you assess each eye individually, with first one closed and then the other. If you see any of the lines or shapes as gray instead of black, then it is likely that you have astigmatism and you should see an eye care professional.

Different factors, such as lighting, distance from the computer screen or printout, and eyestrain can affect the outcome, which is why these online tests are simply a pre-test tool and not a substitute for an exam conducted by a professional.

Treatment

There are several different ways to treat astigmatism. Of course, eye glasses are the most commonly used treatment. The most costly treatment is with refractive laser eye surgery which reshapes the cornea. The risk and perceived cost of this surgery deters many people from taking this course of treatment. Toric contact lenses are the most unobtrusive long term alternative to surgery, and recent advances have brought the cost of these lenses down considerably.

When toric contact lenses first appeared they were available only in RGP. While RGP toric lenses are still available and provide good value for long term use, most manufacturers have also started make soft toric contact lenses. These are available in standard daily wear format, and these last about a year. You can also purchase disposable daily wear toric contact lenses, which last for periods ranging from a day to a month of daily wear.

Astigmatism sufferers, who once had only one option to treat their condition, now have several alternatives to choose from. Toric contact lenses are one of the most unobtrusive, cost effective, and risk-neutral of these choices.

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Astigmatism Guide Astigmatism is one of a group of eye conditions, called refractive errors, that cause a disturbance in the way light rays are focused within the eye. This occurs when the cornea, a thin sheet of clear tissue covering the eye around the pupil, is irregularly curved. Normally, the eye is a near-perfect sphere, but in astigmatism, the front surface of the cornea is curved more in one direction than in the other--more football-shaped than basketball-shaped. In fact, most astigmatic corneas have two axes of irregular curvature, one flatter than the other. This distortion causes an inability of the eye to focus light rays correctly onto the retina and may result in vision resembling the distortion in a funhouse mirror. This blurred vision applies to objects at all distances, though the condition may be accompanied by near- or far-sightedness. Unequal astigmatism may ultimately lead to amblyopia, or "lazy eye," a condition in which one eye suffers loss of acuity due to the patient favoring his or her other, less astigmatic, eye. Astigmatism can be Mild or Serious Not all people with astigmatism require medical assistance; the distortion can be fairly mild. Some experts believe all human beings have a degree of astigmatism. However, in many cases the curvature of the eye is more severe, and corrective lenses must be used to refocus light rays in the eye. These corrective aids may take the form of spectacles or contact lenses. Many astigmatic patients use specially curved contact lenses called toric lenses, which include an additional power element called a cylinder. These lenses bend incoming light farther in one direction than in another in order to oppose the refractive effects of eye curvature. Astigmatism may also be corrected by a refractive surgical procedure called laser-assisted in-situ keratomileusis, or lasik for short. Radio keratotomy and astigmatic keratotomy are two older forms of corrective corneal surgery. Symptoms Symptoms of astigmatism include blurring or distortion of images at all distances, plus headache, fatigue, eye irritation, and frequent squinting. These symptoms may grow more intense as a person gets older, so it's a good idea to get regular eye check-ups, especially if a person has already been fitted for corrective lenses. The patient's prescription may need to be altered in order to correct for changes in eye curvature. Diagnosis Many eye care clinics and contact suppliers have tests for astigmatism posted on their websites. The most common test is a radial design with lines arranged in angles from zero to 180 degrees, similar to that associated with the sun as it rises above the horizon. Other test designs include a specially printed eye chart and square shapes made of a series of lines. For each of these tests, you assess each eye individually, with first one closed and then the other. If you see any of the lines or shapes as gray instead of black, then it is likely that you have astigmatism and you should see an eye care professional. Different factors, such as lighting, distance from the computer screen or printout, and eyestrain can affect the outcome, which is why these online tests are simply a pre-test tool and not a substitute for an exam conducted by a professional. Treatment There are several different ways to treat astigmatism. Of course, eye glasses are the most commonly used treatment. The most costly treatment is with refractive laser eye surgery which reshapes the cornea. The risk and perceived cost of this surgery deters many people from taking this course of treatment. Toric contact lenses are the most unobtrusive long term alternative to surgery, and recent advances have brought the cost of these lenses down considerably. When toric contact lenses first appeared they were available only in RGP. While RGP toric lenses are still available and provide good value for long term use, most manufacturers have also started make soft toric contact lenses. These are available in standard daily wear format, and these last about a year. You can also purchase disposable daily wear toric contact lenses, which last for periods ranging from a day to a month of daily wear. Astigmatism sufferers, who once had only one option to treat their condition, now have several alternatives to choose from. Toric contact lenses are one of the most unobtrusive, cost effective, and risk-neutral of these choices.	Menu Directory Contact Lenses Home Who We Shop With Shopping Guide Bifocal Lenses Colored Lenses Cosmetic Lenses Disposable Lenses Gas Permeable Soft Lenses Toric Lenses Education Astigmatism Pinkeye History of Contacts Inserting Contacts Removing Contacts Contact Lens Glossary Popular Brands Ciba Vision Wesley Jessen CooperVision Johnson & Johnson Lasik Guide Lasik Guide Lasik Directory More Info Visit Our Lasik Directory Today Visit our lasik directory for geographical listings of lasik surgeons across the U.S.!