Facts About Astigmatism
While astigmatism may seem like a long, frightening word, it is not in fact a terrible eye disease or threatening condition. Like nearsightedness and farsightedness, astigmatism is a refractive error caused by an abnormality(s) in the patient’s cornea. Such abnormalities of the lens do not allow the light (ie the image we see) to focus on a single spot on the retina, but instead multiple points causing distorted or blurred vision to some degree at all distances. If the astigmatism is left uncorrected, eyestrain and headaches can occur particularly after long visual tasks.
Patients with astigmatisms have irregularly shaped corneas, more like a football shape vs. a baseball. Another way to envision the curvature of astigmatisms is by thinking of the lens as a face of a clock with a meridian running from 12 to 6 and another running from 9 to 3, and so on. Also, meridians that are perpendicular to each other are called principal meridians. This irregularity of the cornea causes light to focus on multiple points, usually in front, behind the cornea or both, instead of at one single point on the retina. The retina is what processes the image and sends it to the brain via the optic nerve.
There are a few types of astigmatisms and they are called:
- Myopic astigmatism – nearsighted, meaning one or both principal are nearsighted and there is difficulty seeing far away.
- Hyperopic astigmatism – farsighted, meaning one or both principal meridians are farsighted and there is difficulty seeing objects close by.
- Mixed astigmatism – is self-explanatory.
- Regular astigmatism – that the principal meridians are 90 degrees (perpendicular) to each other
- Irregular astigmatism – the meridians are not perpendicular to each other
Regular corneal astigmatism is the most common type giving the lens a football shape.
Why Lasik for Astigmatism is Your Solution!
LASIK can permanently and fully correct astigmatism with great success. The refractive surgery reshapes the cornea to eliminate the asymmetrical shape by creating a hinged flap on the surface of the eye, folding the layer back and using another laser to remove the tissue with a precise and controlled laser to achieve the desired shape, eliminating the astigmatism. The patient is put under local anesthetic and the procedure very little time at all. Patients with mild to moderate astigmatisms up to a certain degree stand to benefit the most from LASIK surgery to correct their astigmatism because the greater degree the astigmatism is, the more tissue that is needed to be removed to achieve desirable results. While glasses and contacts lenses compensate and temporarily fix astigmatism vision impairments, LASIK is a very successful, permanent solution.