A is for Astigmatism. Astigmatism is when an eye has an abnormal curvature – instead of being round like a basketball, it may be shaped more like a football.
Answers to Frequently Asked Questions
What is astigmatism?
Astigmatism is when the eye has an abnormally shaped, or abnormally curved, cornea (the clear front cover of the eye) or an abnormally curved lens inside the eye. Most eyes are round like a baseball or basketball. If a cornea is oblong – shaped more like an American football, for example – then it distorts the light that is projected onto the retina, the light-sensitive tissue at the back of the eye, and the patient sees a blurred or distorted image.
Can astigmatism be treated?
Yes, astigmatism can oftentimes be corrected with glasses or special contact lenses.However, while nearsightedness or farsightedness can be corrected with simple spherical lenses, astigmatism requires a cylinder, which adds more curvature and focusing power in one axis than the other so that the patient’s images aren’t distorted.
How common is astigmatism in children?
Astigmatism is one of the most common childhood vision problems. About 10% of preschool children have astigmatism, according to a study funded by the National Eye Institute (NEI), which is part of the National Institutes of Health (NIH). The same study found that it is particularly prevalent among very young children, with 23 percent of children between the ages of 6 months and 1 year old having astigmatism. But many grow out of it. By the times children are 5 to 6 years old, only 9 percent had astigmatism.1
Is astigmatism more common among certain ethnicities?
Yes. The NEI study of preschool children found astigmatism had a prevalence of 13 percent among Hispanic children, compared to 9 percent for African-American children and 6 percent for non-Hispanic white children. 1
Why is astigmatism called a “refractive error”?
Astigmatism – along with nearsightedness (myopia) and farsightedness (hyperopia) – is an eye abnormality categorized as a “refractive error” because it impacts how the eyes “refract,” or bend, light that is projected onto the retina. Astigmatism frequently occurs along with other refractive errors such as nearsightedness or farsightedness.
Is astigmatism considered a risk factor for amblyopia?
Yes, if it is severe enough. According to the revised guidelines, issued in 2012, from the American Association for Pediatric Ophthalmology and Strabismus, astigmatism can be a risk factor for amblyopia, the leading cause of vision loss among children, depending on the severity of the astigmatism and the age of the child. AAPOS guidelines recommend that any vision screening with a photoscreener or other instrument should screen for astigmatism greater than 2 diopters if the child is between the ages of 12 months and 48 months, and greater than 1.5 diopters if the child is older than 48 months. A diopter is a measure of the power of the lens that would be needed to correct a child’s vision.
Can astigmatism be detected by pediatric vision screening?
Yes. Pediatric vision screening devices, like the iScreen Vision Screener 3000 photoscreener, are designed to screen for refractive errors such as astigmatism, myopia, and hyperopia, among other visual problems. This type of pediatric vision screening might be referred to as Astigmatism Vision Screening, Astigmatism Vision Testing, Pediatric Astigmatism Vision Screening, or Pediatric Astigmatism Vision Testing.
What are some of the possible symptoms of astigmatism?
- Blurred or distorted vision
- Sensitivity to light
Pediatric Astigmatism Vision Screening & Detection FAQs
These FAQs discuss topics including: Astigmatism, Astigmatism Vision Screening, Astigmatism Vision Testing, Pediatric Astigmatism Vision Screening, and Pediatric Astigmatism Vision Testing.
1. Roberta McKean-Cowdin, Rohit Varma, Susan A. Cotter, Kristina Tarczy-Hornoch, et al. Risk Factors for Astigmatism in Preschool Children: The Multi-Ethnic Pediatric Eye Disease and Baltimore Pediatric Eye Disease Studies. Ophthalmology. 2011 Aug 19.