LASIK is one of the most popular elective vision-correction procedures. With so much discussion surrounding the topic, it’s no surprise that myths and inaccuracies creep into the conversation. For example: the fallacy that LASIK does not correct astigmatism, or those with astigmatism are not candidates for LASIK.
The truth is, ophthalmologists use LASIK to correct a variety of refractive errors, including myopia (nearsightedness), hyperopia (farsightedness) and astigmatism.
What is astigmatism?
Astigmatism is blurred or distorted vision resulting from a cornea or lens that is curved asymmetrically. The shape becomes less like a basketball and more like an American football. This causes the light entering the eye to bend unequally, producing sharp vision in some areas and blurry images in others. It can be quite common: In a recent study, more than a quarter of schoolchildren examined were found to have astigmatism.
The cause of astigmatism is imprecisely defined, though it is thought to be genetic. Astigmatism often accompanies myopia or hyperopia. It comes in several types, classified based upon the way in which the cornea is shaped:
- In myopic astigmatism, one or both meridians are nearsighted. (Meridians describe the axes of the eyes, both vertical and horizontal.)
- In hyperopic astigmatism, one or both meridians are farsighted.
- In mixed astigmatism, one meridian is myopic, and the other meridian is hyperopic.
How does LASIK help?
If only a small amount of astigmatism is present, laser correction may not be necessary. However, if astigmatism is impairing vision, LASIK is a viable option.
During the LASIK procedure, a surgeon uses a laser to reshape the cornea, making it more spherical and correcting the way that it will bend and focus light.
For some astigmatic patients, LASIK offers more benefits than glasses or contacts. LASIK improves eyesight across the entire visual field, versus just the portion of the visual field that’s covered by prescription eyewear.
How do I know if LASIK can correct my astigmatism?
While most types of astigmatism can be corrected by LASIK, a few cannot. Irregular astigmatism may not be able to be corrected by LASIK. A condition called keratoconus, in which the cornea bulges in a cone shape, while causing astigmatism, should never be treated by LASIK. An exam by a qualified LASIK specialist should be completed to determine candidacy.
Astigmatic patients generally pay a higher price for LASIK. And, while it may correct astigmatism, LASIK cannot prevent a patient from needing reading glasses later in life.
If you have astigmatism, LASIK may reduce your dependence on glasses and contacts. Talk to a LASIK specialist about what options are best for you.