To begin: You don’t have “a stigmatism” – you have astigmatism.

Definition:

Astigmatism is a refractive error, like nearsightedness and farsightedness, meaning that it is not a ‘health’ problem or a disease of the eye itself. Simply put, it is a problem with how the eye focuses light – the light fails to come to a single focus on the retina to produce clear vision, rather multiple focal points occur, either in front of the retina or behind it (or both).

Symptoms:

Generally astigmatism cause one’s vision to be blurred or distorted to some degree at all distances, if gone uncorrected astigmatism cause severe eyestrain and headaches, especially so after reading or other prolonged visual tasks. Another common symptom of astigmatism is squinting.

Causes:

Astigmatism most usually is caused by an irregularly shaped cornea. Instead of the cornea having a symmetrically round shape – it is shaped like a football, rather than a baseball, with one meridian being significantly more curved than the meridian perpendicular to it. The steepest and flattest meridians of an eye with astigmatism are called the principal meridians. In some special cases, the astigmatism is caused by the shape of the lens “inside” the eye. This is called lenticular astigmatism, to be able to differentiate from the more common corneal astigmatism.

Types:

  • Myopic astigmatism. One or both principal meridians of the eye are nearsighted. (If both meridians are nearsighted, they are myopic in differing degree.)
  • Hyperopic astigmatism. One or both principal meridians are farsighted. (If both are farsighted, they are hyperopic in differing degree.)
  • Mixed astigmatism. One principal meridian is nearsighted, and the other is farsighted. Astigmatism also is classified as regular or irregular. In regular astigmatism, the principal meridians are 90 degrees apart (perpendicular to each other). In irregular astigmatism, the principal meridians are not perpendicular. Most astigmatism is regular corneal astigmatism, which gives the front surface of the eye a football shape.

(Definition of types from: American Optometric Association)

Irregular astigmatism can result from an eye injury that has caused scarring on the cornea, from certain types of an eye surgery or from keratoconus, a disease that causes a gradual thinning of the cornea.

How common is Astigmatism?

Astigmatism usually occurs early in life, so it is most important to get an early eye exam for your child to avoid any vision problems that might occur in school from this uncorrected condition. Statistics show that children in the United States between the ages of 5 to 17 years of a study of 2, 523 (American youngsters) that 28% of those suffered from astigmatism. There seems to be some significant prevalence based on ethnicity as well, with Asian and Hispanic children having astigmatism conditions over white children.

Test:

Astigmatism is detected during a routine eye exam with the same instruments and techniques used for the detection of nearsightedness and farsightedness. Your eye doctor can estimate the amount of astigmatism you have by shining a light into your eye while manually introducing a series of lenses between the light and your eye.