Astigmatism is a refractive error caused when the shape of an eye is not perfectly round. Contact lenses, glasses and vision correction surgeries are the available treatment options for astigmatism correction.
What Causes Astigmatism?
The human eye is shaped naturally like a sphere. When light goes through the eye under normal conditions, it bends or refracts evenly, producing a clear image of the object. Conversely, a person who suffers from astigmatism has eyes shaped more like the back of a spoon or a football. As a result, when light goes through an astigmatic eye it bends more to one side than the other, letting only fraction of the image to be concentrated at one time.
Types of Astigmatism
Astigmatism can be classified into many types, each requiring different levels of astigmatism correction. There are five major types of astigmatism:
1. Regular Astigmatism
Principal meridian of the eyes are the x-axis and the y-axis of the eye diameter. The x-axis is the distance between the horizontal borders of the eye whereas the y-axis is the distance between the longitudinal borders. Regular astigmatism occurs when the x and y axis are perpendicular to one another, exactly 90 degrees apart. It is the most common type of astigmatism in which the eye is shaped like a rugby ball.
2. Irregular Astigmatism
Often occurs because of an eye surgery, irregular astigmatism is the type of astigmatism where the principle axes of the eye are not perpendicular to one another. In this form of astigmatism, the cornea is scarred from different types of surgeries or through thinning of the cornea itself.
3. Hyperopic Astigmatism
In hyperopic astigmatism, one of the eyes or even both may be suffering from the condition of astigmatism as well as farsightedness. If both of the eyes are hyperopic, then the angle of refraction might differ between them.
4. Myopic Astigmatism
In myopic astigmatism, either of the eyes or even both may be suffering from the condition of astigmatism as well as myopia. If both of the eyes are myopic, then the angle of refraction might differ between them.
5. Mixed Astigmatism
In the mixed astigmatism, the eyes are a victim of all three vision problems. Astigmatism occurs with near-sightedness in one eye and far-sightedness in the other.
How to Treat Astigmatism?
All types of astigmatism can be treated with either contact lenses or eyeglasses. If a person has mild astigmatism, he might not need any corrective lenses at all. However if astigmatism persists with other eye vision problems as well, the corrective lenses will be required at all costs.
1. Refractive Surgery:
A recent and well developed method for astigmatism treatment, it is changing the morphology of the cornea through laser eye surgery or refractive surgery. There are many types of refractive surgeries and each type is dependent on individual basis.
2. Toric Lenses:
Special contact lenses called Toric Lenses are recommended by doctors for astigmatism correction. Toric lenses are soft lenses with a high refraction power to bend the light in one direction more than the other.
3. Gas Permeable Lenses:
For people with a an extremely high amount of astigmatism, where the toric lenses fail to work and patient refuses to get a surgery, the astigmatism can be corrected through gas permeable rigid toric lenses instead.
Astigmatism is commonly misunderstood as a disease, when it is merely a deviation in the eye and most common of the vision problems. Almost 47% of the people who suffer from either myopia or hyperopia are also a victim of astigmatism as well. Due to the available astigmatism correction methods, this vision problem is henceforth not a case to worry about.