Astigmatism is a common vision problem that occurs when the cornea (the clear front part of the eye) or lens (the structure inside the eye that focuses light) is irregularly shaped. In order to cause the image to distort on the retina (the light-sensitive layer at the back of the eye), light bends unevenly. Symptoms of astigmatism include blurred vision, eye strain, headaches, and difficulty seeing at night. Astigmatism is discussed in this blog post in terms of its causes, symptoms, diagnosis, treatment, and prevention.
Causes of Astigmatism
A combination of genetic and environmental factors may be responsible for astigmatism, but it is unknown exactly how it occurs. A person may inherit astigmatism from their parents, or they may develop it later in life after exposure to certain triggers. Common triggers of astigmatism include:
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Surgery or trauma to the eye can damage or alter the shape of the cornea or lens.
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Astigmatism can be caused or worsened by certain eye diseases, such as keratoconus (a condition that causes the cornea to thin and bulge out).
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A person's eyes may change shape and lose elasticity as they age, resulting in astigmatism.
Symptoms of Astigmatism
Astigmatism symptoms vary from person to person depending on the degree and type of astigmatism. Some people may have mild or no symptoms, while others may have significant vision problems. The most common symptoms are:
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In low light or at a distance, objects may appear fuzzy or stretched out.
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After prolonged or intense visual tasks, such as reading, working on a computer, or driving, the eyes can feel tired, sore, or dry.
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Astigmatism may cause headaches or throbbing in the eyes.
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To improve focus and clarity, the eyes may squint or partially close.
Diagnosis of Astigmatism
Astigmatism can be diagnosed through a comprehensive eye exam that includes a medical history and a visual acuity test; the doctor may also use various instruments and techniques to measure the shape and function of the eye.
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The keratometry device measures the cornea's curvature by reflecting light off its surface and analyzing its reflection.
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The refraction test consists of placing different lenses in front of the eye and asking which one provides the clearest vision.
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By shining a beam into the eye and detecting its reflection, the autorefractor measures how the eye focuses light.
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A pattern of light is projected onto the cornea and its image is captured to create a detailed map of its shape and irregularities.
Treatment of Astigmatism
Several treatment options can be used to correct astigmatism in order to improve vision quality and comfort. The most common treatment options are:
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These lenses are worn on the face to compensate for the irregular shape of the cornea or lens. They are easy to use and maintain as well as correct mild to severe astigmatism.
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Compared to eyeglasses, contact lenses provide better peripheral vision and cosmetic appearance, but they require more care and hygiene.
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A refractive surgery involves reshaping the cornea with a laser or blade to permanently correct astigmatism. Various refractive surgeries are available, including LASIK (laser-assisted in situ keratomileusis), PRK (photorefractive keratectomy), LASEK (laser-assisted subepithelial keratectomy), and Epi-LASIK (epithelial laser in situ keratomileusis). Although refractive surgery can provide long-term results, there are risks and complications involved.
Prevention of Astigmatism
There is no definitive way to prevent astigmatism, but some steps can be taken to reduce its effects on vision and health. These steps include:
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A routine eye exam can help detect and treat astigmatism early and prevent it from getting worse.
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When engaging in activities posing a risk of eye injury or exposure to harmful substances, wearing protective eyewear can prevent corneal or lens damage.
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Follow proper instructions when wearing eyeglasses or contact lenses to prevent infections and irritations that may affect the eye's shape or function.
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Maintaining a healthy lifestyle involves eating a balanced diet, staying hydrated, getting enough sleep, managing stress, and avoiding smoking.
Conclusion
When the cornea or lens of the eye has an irregular shape, astigmatism occurs as a common vision disorder. Astigmatism causes light to bend unevenly and distort the image on the retina. It can affect people of all ages and cause blurred vision, eye strain, headaches, and difficulty seeing at night. An eye doctor can diagnose astigmatism based on a medical history, physical examination, and some tests. In order to improve vision quality and comfort, astigmatism can be corrected using eyeglasses, contact lenses, or refractive surgery. Regular eye exams, eye protection, eye care, and a healthy lifestyle can also help manage astigmatism. With the right care and correction, people with astigmatism can enjoy clear and comfortable vision. Astigmatism is treatable and does not have to interfere with everyday activities and quality of life.
