The Eye Institute for Medicine & Surgery
Eye Doctor Melbourne FL
(321) 722-4443

Astigmatic Correction

What is Astigmatism?

Astigmatism is a common vision impairment caused by the shape of the eye.

Ideally, the eye is round, like a basketball divided in half.  Some people, however, have eyes with a cornea shaped somewhat like a football. When this is the case, the person is said to have astigmatism.  Astigmatism causes distortion of a person’s vision, which people most frequently describe as an overall blurriness and inability to see things sharply and clearly.

Generally there are three surgical methods for correcting astigmatism. They are implantation of a toric lens, limbal relaxing incisions, or LASIK.

Lenses for Astigmatism:

(AcrySof Toric and Tecnis Toric)

Toric IOLs are designed to correct astigmatism at the time of cataract surgery, allowing for clear distance vision while greatly reducing or eliminating the need for eyeglasses.   If you have significant astigmatism which makes distance vision activities such as driving, sports, shopping, movies and television difficult without eyeglasses, a toric IOL may help provide the spectacle freedom from glasses you have been seeking.   Note:  Toric IOLs provide correction for distance, but you will likely still require reading glasses.

AcrySof Toric TECNIS Toric


Limbal Relaxing Incisions

The outer layer of the eye can be divided into three areas: the cornea, the sclera and the limbus. The cornea is the clear part, or the window, that covers the iris and the pupil. The sclera is the white part of the eye.The limbus is the thin area that connects the cornea and the sclera.

Limbal relaxing incisions (LRIs) treat low to moderate degrees of astigmatism. Astigmatism is said to occur when the cornea is elliptical rather than spherical. Stated differently, astigmatism exists when the cornea is shaped more life a football divided in half, rather than a basketball divided in half. 

Slight astigmatism can cause blurred vision while strong astigmatism can cause headaches and eyestrain at all distances. As the name suggests, when the decision has been made to attempt to correct astigmatism via LRI, your surgeon will make small relaxing incisions in the limbus, thus allowing the cornea to become more rounded as it heals.  LRIs are placed at the very edge of the cornea (in the limbus) on the steepest meridians.

Limbal Relaxing Incisions are for patients who:

  • have astigmatism
  • want to reduce or eliminate their dependence on eyeglasses or contact lenses
  • have no serious autoimmune disorders or corneal health issues

LRI incisions are usually made at the time of cataract surgery – though they may be performed later - to reduce or eliminate astigmatism and thus to attempt to enhance vision without the need for eyeglasses.  A near prescription will usually still be necessary to read and do close work, even if LRI is successful.  Our physicians will discuss the options that are most likely to help you to achieve your desired results.  Occasionally, LRI will need to be repeated in order that the patient receives his or her maximum benefit from the procedure.

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LASIK as a means of correcting astigmatism

While most people know that nearsightedness (myopia) and farsightedness (hyperopia) can be corrected with LASIK or PRK laser vision correction surgery, fewer are aware that these procedures can also correct astigmatism.  Astigmatism is an extremely common condition, present in approximately one in six people.
Astigmatism is most commonly corrected with eyeglasses or contact lenses, but the only solution that can fixes the underlying problem is refractive surgery, such as LASIK, PRK, the implanting of a Toric Lens Implant or performing Limbal Relaxing Incisions.

Corrective Lenses vs. LASIK

Astigmatism results from having a cornea or lens that is oblong or otherwise atypically shaped. Even a slight defect in the shape of your lens or cornea can cause images to be out of focus at certain angles, which is the main symptom of astigmatism. Eyeglasses and contacts can correct astigmatism, but they cannot change the actual shape of your eye to permanently fix the problem. When you add up the cost of glasses and contacts over the years, a permanent fix for astigmatism with LASIK vision correction surgery can be a cost-effective alternative.
In addition, wearing contact lenses and especially eyeglasses can get in the way of an active lifestyle that involves sports like skiing or swimming, which normally require goggles. For people with astigmatism who also like to exercise and play sports, LASIK surgery can provide freedom from the hassle of glasses and contacts. LASIK has also become popular for people with astigmatism who work in occupations that require clear vision, such as pilots and surgeons.

The Refractive Specialists of The Eye Institute for Medicine & Surgery offer LASIK surgery to appropriate candidates as a safe and effective means of correcting astigmatism. Our diagnostic equipment allows us to create an individualized treatment plan for your eye and the degree of astigmatism correction you need.