Understanding Astigmatism -- Diagnosis & Treatment
What Are the Treatments for Astigmatism?
Astigmatism can be corrected with glasses, contact lenses, or surgery. However, some doctors believe that people with very small amounts of astigmatism are best left untreated.
Eyeglass lenses are shaped to counteract the shape of the cornea or lens that's causing blurred vision. Eyeglasses work well when the patient looks straight ahead. But, depending on the specific correction, the glasses can make the floor or walls appear to tilt. This usually goes away completely as the patient gives the glasses a chance to work and gets used to them. Patients with significant astigmatism usually adjust to their first pair of glasses within a week or so. If they don't seem to be working, ask your doctor to recheck the prescription and verify the correction in your new glasses.
Specially designed contact lenses can also correct astigmatism. All contact lenses rotate when a person blinks. The lenses used for astigmatism -- called "toric" lenses -- are designed to return to the same position each time the wearer blinks. Thus, toric contact lenses compensate for any abnormal curvature in your cornea.
Laser eye surgery (LASIK). In this technique, the surgeon uses a laser to reshape the cornea so it can focus light rays better. After numbing the eye with eyedrops, a sterile mechanical device (or another laser) creates a thin, superficial flap in your cornea. The surgeon lifts and sweeps back the flap with a tiny instrument. The central portion of the deeper corneal layers is exposed for laser treatment. Next, you will hear clicking noises as a laser precisely sculpts the inner cornea. The doctor then sweeps the flap back to its original position. Finally, the doctor administers anti-inflammatory and antibiotic eye drops. Once the doctor covers your eyes with transparent shields, you're ready to go home.
The cost of this surgery ranges from $700-$3,500 per eye. Because the procedure is done by choice to replace eyeglasses, LASIK is rarely covered by health insurance.
There are some downsides to LASIK surgery which highlights the need to seek a qualified LASIK surgeon to minimize risks:
- The surgery may occasionally overcorrect or undercorrect your refractive error, requiring follow-up surgery.
- You may see a glare around lights that impairs your vision at night. However, newer procedures and screening tests are designed to minimize glare.
- You may have increased dryness of the eye.
- If you are 40 years old or older, you may still need to wear glasses for reading. This can be avoided by choosing a monovision technique in which the dominant eye is focused for distance and the non-dominant eye is focused for near vision. Although it seems like this would result in visual confusion and focusing difficulties, most people adjust to this since the imbalance is minimal. Monovision can be demonstrated with the use of contact lenses or handheld lenses before having monovision LASIK performed.
Astigmatic keratotomy, or limbal relaxing incisions, is another procedure used to correct astigmatism. The surgeon makes tiny cuts into the cornea that are strategically placed on the steepest curves. This allows light to focus more precisely on the retina. This procedure is gradually being replaced by laser surgery for higher degrees of astigmatism.