Astigmatism is a common refractive error of the eye that occurs when the cornea or lens has an irregular shape, leading to blurred or distorted vision. In a normal eye, the cornea and lens have a round or spherical shape, allowing light to focus on a single point on the retina. In eyes with astigmatism, the cornea or lens is more oval or football-shaped, causing light to focus on multiple points rather than a single point.
There are two main types of astigmatism:
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Corneal Astigmatism: This is the more common type and occurs when the cornea (the clear front surface of the eye) has an irregular shape. Instead of being spherical, it may be shaped more like a football, with varying degrees of curvature in different meridians.
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Lenticular Astigmatism: This type of astigmatism is less common and is related to irregularities in the shape of the eye's lens.
Common symptoms of astigmatism include:
- Blurred or distorted vision, both at near and far distances.
- Eye strain and discomfort.
- Headaches.
- Squinting to see clearly.
- Difficulty with night vision.
Astigmatism often occurs in combination with nearsightedness (myopia) or farsightedness (hyperopia). The diagnosis is typically made through a comprehensive eye examination, which may include the use of a phoropter and other specialized instruments.
Correction for astigmatism is usually achieved with eyeglasses or contact lenses that have a special cylindrical lens prescription. Refractive surgery, such as LASIK or PRK, can also be an option for some individuals with astigmatism.
It's important to have regular eye exams to detect and correct astigmatism early, as uncorrected astigmatism can lead to eye strain, headaches, and a decrease in overall visual acuity. If you suspect you have astigmatism or are experiencing vision problems, it's advisable to consult with an eye care professional for a thorough examination and appropriate treatment options.
