What is Astigmatism?
Pediatric Optometrist in Houston
Astigmatism is a type of refractive error, which means that it affects how your eye focuses light. In an eye with astigmatism, light fails to focus properly on a single point on the retina, which is necessary for clear vision. Instead light falls on multiple focal points in front of your retina, behind your retina, or both.
Astigmatism is typically caused by an irregular shaped cornea (a condition called corneal astigmatism). Instead of the cornea having a round, symmetrical shape it is shaped more like a football, where one meridian is significantly more curved (like a football), refracting the light that enters the eye in a way that distorts your vision. In some cases, astigmatism is caused by the shape of the lens itself (a condition called lenticular astigmatism).
The best way to describe meridians is to think of your eye as a clock face, with one line connecting the 12 and 6 and another connecting the 3 and 9. These two lines are called the principal meridians. Between each of your principal meridians are other meridians. Astigmatism can occur along any meridian.
There are three types of astigmatism: Myopic astigmatism, hyperopic astigmatism, and mixed astigmatism.
- Myopic astigmatism: Myopic astigmatism occurs when one or both of the principal meridians on the eye are nearsighted.
- Hyperopic astigmatism: Hyperopic astigmatism occurs when one or both of the principal meridians on the eye are farsighted.
- Mixed astigmatism: Mixed astigmatism occurs when one principal meridian is nearsighted and the other is farsighted.
Who Gets Astigmatism?
Astigmatism is incredibly common in the United States affecting approximately one in three people according to the American Academy of Ophthalmology.
You are at a higher risk of developing astigmatism if:
- You have a family history of astigmatism or other eye disorders (such as keratoconus)
- Your cornea has thinned or is scarred
- You are excessively nearsighted, which creates blurry vision at a distance
- You are excessively farsighted, which creates blurry vision up close
- You have undergone some types of eye surgery such as cataract surgery.
- Your likelihood of having an astigmatism is also influenced at last partially by your ethnic group. According to a 2003 study conducted by the American Medical Association individuals of Asian or Hispanic descent are statistically more likely to have astigmatism than other ethnic groups. Of the 2523 children studied 33.6% of Asian children and 36.9% of Hispanic children had some degree of astigmatism, compared to only 20.0% of African American children and 26.4% of Caucasian children.
Pediatric Optometrist in Houston.
Myopia Alternatives, Orthokeratology Doctor in Houston, Pediatric Optometrist in Houston, Pediatric Eye Clinic, Pedro Gomez OD, Pediatric Optometry in Houston, Ortho-K Doctor in Houston, Orthokeratology Doctor in Houston, Non Surgical Corneal Molding Doctor in Houston, Non-Surgical Vision Correction Doctor in Houston, Ortho-K Specialized in Houston, Orthokeratology Specialized in Houston, Non Surgical Corneal Molding Specialized in Houston, Non-Surgical Vision Correction Specialized in Houston, Keratoconus Therapy in Houston, Keratoconus Doctor in Houston, Keratoconus Specialized in Houston, Wave Contact Lenses in Houston, Strabismus treatment in Houston, Dry Eye treatment in Houston