Refractive errors refer to the irregular shape of the eye, which results in light being reflected incorrectly in front of, or behind the retina. In the case of astigmatism, multiple irregularities of the eyes shape cause light to be reflected in multiple spots within the eye.
There are three primary types of astigmatism:
Myopic astigmatism – The eye’s shape causes vision to be nearsighted
Hyperopia astigmatism – The shape of the eye results in light being focused behind the retina causing farsighted vision
Mixed astigmatism– Both myopic and hyperopic shaped irregularities cause the eye to focus light on multiple points
Blurry and distorted vision at varying distance are common signs of all 3 types of astigmatism. Eye strain and headaches especially after reading are also signs of the condition. These symptoms are usually the result of sufferers squinting and constantly trying to focus, especially during prolonged visual tasks.
How Common Is Astigmatism?
Research shows that approximately 30 percent of varying populations experience astigmatism. Your eyes can change shape over time, meaning that astigmatism can appear and worsen with age.
Recent studies have shown that American children ages 5-17 have a 28 percent chance of being afflicted by astigmatism. Ethnicity also plays a role in astigmatism, with Asian and Hispanic children having a higher prevalence at 33.6 percent and 36.9 percent respectively. Caucasians and African-Americans have a lower prevalence at 26.4 percent and 20 percent.
Treatment Options And Testing
Astigmatism is usually detected through a routine eye exam. In the same manner that myopia and hyperopia are diagnosed, astigmatism is discovered with the same techniques and instruments. An estimation of the amount of astigmatism is performed via a retinoscopy, where light is directed into the eye while using a series of lenses.
Once astigmatism is diagnosed as the cause of vision problems, one of the following options can be pursued to provide treatment:
Corrective Lenses are the most common method to address astigmatism. Like far and nearsightedness, your optometrist can prescribe a lens shape that corrects for astigmatism.
Contact Lenses correct for visual irregularities in a similar manner that glasses do. A hard lens is used unlike soft contact lenses that some people are accustomed to. Lenses that correct for astigmatism require a long adaptation period so the wearer can become comfortable with them.
LASIK Surgery can also correct most types of astigmatism. This option should be discussed at length with your Optometrist so that the procedure and any side effects are fully understood.