Prescription for Astigmatism

Astigmatism is an eye disorder causing blurred vision to some degree. The condition results from the cornea, or front surface of the eye, not having a normal spherical shape but an asymmetrical one. Very mild cases do not need correction, while others can be corrected with prescription glasses, contact lenses, or refractive surgery.

Identification

• Astigmatism is a frequent secondary diagnosis for both nearsighted and farsighted people. Instead of a sphere, the cornea is shaped like a football or an egg. Astigmatism is very common, and probably goes undiagnosed in many people with mild cases and no other vision problems. An Ohio State University study found that over 28 percent of school-aged children have astigmatism. It is a hereditary condition, and is not caused by activity such as sitting too close to the television, spending too much time on the computer, or reading in dim light.

Considerations

• Mild astigmatism may not cause any symptoms for the person who has it, or it may result in headache and eyestrain. Sometimes children who begin having problems with schoolwork are found to have astigmatism, which can make reading difficult.

Glasses

• Typically people who wear eyeglasses obtain a prescription for astigmatism correction along with their prescription for nearsightedness or farsightedness. For people without these conditions, no prescription may be necessary if the condition is very mild. If people are experiencing eyestrain, headache, or blurred vision, then they do need prescription lenses. Astigmatism can increase and decrease over time, so people with the disorder need to see their eye doctor regularly.

Soft Contact Lenses

• Until the late 1970s, there were no contact lenses for astigmatism, so the condition went uncorrected in contact lens wearers. Then soft contact lenses called toric lenses were invented that would fit the asymmetrical cornea. These lenses are weighted so they do not move around very much. They are sold in disposable and non-disposable types, and are somewhat more expensive than regular soft contacts.

Additional Solutions

• Also, rigid gas permeable lenses became available in the early 1980s as a preferred alternative to hard contacts. These lenses allow air to reach the eye, unlike hard or soft lenses. Because hard lenses and RGPs provide clearer vision than soft contacts, they are the best correction for mild cases of astigmatism. They maintain their shape on the eye and correct astigmatism by a layer of tears between the eye and the lens, and thus usually do not need to be a toric shape. Many people find them as comfortable as soft lenses, particularly people with dry eyes. Eye doctors also can prescribe customized RPG toric lenses.

  Hybrid lenses are another option. They have a gas-permeable center and a soft periphery. This provides the clarity of RPG lenses with the wearing comfort of soft lenses.

  Some people with moderate to severe cases of astigmatism cannot have the condition corrected with contact lenses. If they prefer not to wear glasses, refractive surgery can correct some types of astigmatism and some levels of severity.