O astigmatism is a relatively common visual disorder in the population and is characterized as a eyesight “blurry” (distorted image), regardless of the distance the observer is from the object. Astigmatism is caused by a irregular shape of the cornea or lens. To correct the problem, you can use glasses with proper lenses, contact lenses or even opt for correction surgery.
It is noteworthy that astigmatism can occur alone or in association with other refractive defects, such as farsightedness and nearsightedness. According to data from the Hospital de Olhos de Santa Catarina, astigmatism is one of the most common eye problems and reaches approximately 60% of Brazilians.
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What is Astigmatism?
Astigmatism is a vision problem that is characterized by inadequate focusing of light on the retinal region, being, therefore, a refractive eye error. Inadequate focusing is the result of an irregular shape of the cornea, lens, or both. In people with astigmatism, we often see a more oval cornea, unlike patients who have normal vision, in whom the cornea is round and smooth. The oval shape promotes a
refraction from light to several points, which leads to difficulty in forming only one focal point on the retina.
People with astigmatism have difficulty seeing both near and far, having what is called “blurry” vision. The greater the degree of astigmatism, the greater the distortions in the individual's vision, which makes it difficult to perceive details.
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Causes of Astigmatism
Astigmatism is influenced by genetic factors, however it can also have other causes, such as eye trauma that damaged the cornea. It is important to point out that it is common for children, in the first year of life, to present the problem, however, as they develop, it is corrected. It is noteworthy that children who did not have astigmatism in their first year of life will hardly have the problem in their adulthood.
Astigmatism symptoms
A person may suspect astigmatism when they notice the following symptoms:
- Difficulty seeing up close and also from afar;
- Blurred vision, as if looking through corrugated glass;
- Light sensitivity;
- Eye strain;
- Headaches caused by visual effort;
- Difficulty distinguishing details, such as identifying similar numbers and letters, such as M and N or 0 and 8.
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Astigmatism diagnosis
The diagnosis of astigmatism is made by the ophthalmologist doctor in the eye office. During the consultation, the doctor performs a series of tests that can detect this vision problem, such as the test in which the patient needs to read a projection with letters and numbers and the use of a device in which several lenses are placed in front of the patient to indicate which lens is the best for their eyesight.
Astigmatism treatment
Astigmatism is a problem that can be treated through the use of contact lenses, glasses or even through surgery. Lenses and glasses are intended to ensure that light rays are concentrated in a single point. Toric lenses are those contact lenses recommended for people with astigmatism. The lenses of eyeglasses are called cylindrical.
With regard to surgery, it is considered safe and effective, however not recommended for all patients who have the problem.. To patients who have other eye diseases, such as glaucoma and keratoconus, it is not recommended.
It is important to emphasize that only the ophthalmologist can correctly diagnose astigmatism and indicate the best treatment in each case. Knife periodic ophthalmologist appointments, as some diseases are silent and can trigger visual impairment. Take good care of your eye health.
By Vanessa Sardinha dos Santos
Biology teacher
Would you like to reference this text in a school or academic work? Look:
SANTOS, Vanessa Sardinha dos. "Astigmatism"; Brazil School. Available in: https://brasilescola.uol.com.br/doencas/astigmatismo.htm. Accessed on June 28, 2021.
