However, they do know it tends to be related to our genetics, so you are more likely to inherit it if it runs in your family. Astigmatism can also be acquired after an eye injury, disease, or surgery.
There are two types of astigmatism — regular or irregular — classified by their meridians, or sections of the eye formed by imaginary lines drawn over the eye that intersect at the pupil. A healthy eye has a spherical cornea or lens, meaning the curves are the same. However, an eye with astigmatism has a steep curve and a flat curve, also known as the two principal meridians. Regular astigmatism is when the two principal meridians are 90 degrees apart, with one meridian being steeper than the other.
This type of astigmatism is most common and can be corrected by glasses, contact lenses, or laser surgery. In with-the-rule astigmatism, your cornea is shaped like a football lying on the ground with the steepest curves running vertically. This type of astigmatism is most common in younger people. With against-the-rule astigmatism, your cornea is shaped like a football on a tee with the steepest curves running horizontally. This type of astigmatism is more common in older adults.
Whereas regular astigmatism occurs when the two principal medians are always at right angles, irregular astigmatism occurs when the two principal medians are not symmetric.
In other words, the curvature is uneven, and this makes it harder to correct than regular astigmatism. This type of astigmatism is typically caused by disease, such as keratoconus gradual thinning of the cornea , corneal degeneration, corneal scarring, or ocular surface disease.
You can also have astigmatism combined with other refractive errors. This imperfection results in blurred vision. Astigmatism often occurs with myopia nearsightedness or hyperopia farsightedness :. Light rays focus in front of the retina in the myopic eye, making objects in the distance blurred. Individuals who have myopia with astigmatism experience even worse blurring due to the refractive error caused by mismatched curvatures of the cornea or lens.
In people who are farsighted, the light focuses beyond the retina. Individuals with hyperopia and astigmatism experience blur the closer items become. In people with mixed astigmatism, one curvature of the cornea or lens focuses light in front of the retina and the other focuses light behind the retina.
To be diagnosed with astigmatism, you must be examined by your eye doctor. The American Academy of Ophthalmology identifies three instruments that an eye doctor uses to measure astigmatism :. Because the curvature of your cornea and lens differs from others who share the condition, the symptoms of astigmatism can differ from one sufferer to the next. Generally, the symptoms of astigmatism include:. Lenses temporary or refractive surgery permanent are used to correct astigmatism.
If myopia or hyperopia are also present in addition to astigmatism, these conditions must also be corrected. Below are 8 exercises you can do at home to treat astigmatism. The exercise should be done in the following steps: Place your thumb over your nose at a degree angle. Keep it there for seconds and then bring it back. Make sure your eyes follow your thumb. Repeat this for all clock positions. Exercise 2. Eye Massage Benefit: This exercise restores the shape of the cornea.
The exercise should be done in the following steps: Close your eyes and then place two fingers on each of your eyelids. By applying gentle pressure, slowly move your fingers in a circular motion from top to bottom and from right to left. Move your fingers clockwise as well as anti-clockwise. Repeat it for 10—15 times, 2 to 4 times a day.
The exercise should be done in the following steps: Pull out a book. Place an object next to it. After reading a paragraph from the book, focus on the object. Continue doing this until your eyes start to feel tired. The exercise should be done in the following steps: Take a break from writing, reading, or staring at the computer.
Focus on other objects in the distance for at least 20 seconds Repeat this exercise as many times as possible in a day. The exercise should be done in the following steps: Look in the mirror to find out if you tilt your head to one side. Each of these can be used in not only correcting astigmatism but also in correcting near or long-sightedness at the same time. The way in which laser eye surgery corrects astigmatism is by removing a small amount of corneal tissue in order to correct the asymmetrical curvature of the cornea.
This, in turn, will make your vision clearer. A comprehensive examination by a laser eye surgeon will determine if this procedure is appropriate for you.
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