What you need to know about Astigmatism
Over the years, people have been misunderstanding astigmatism – in fact, it is an eyesight problem that has been most misunderstood by some patients and their relatives. You are likely to face the ridicules from people around you when you call it stigmatism, actually, no one can have stigmatism as an eyesight issue – the correct word is Astigmatism, which is a type of eyesight problem you can suffer or have.
You may be wondering what astigmatism really means, anyway, like short sightedness and long sightedness, it is a refractive error, meaning it is a vision problem with how the eyes gets light focused. Any eye affected with astigmatism, light do not come to a single focus successfully on the retina to create clear vision, rather, the occurrence of multiple focus points takes place; it is usually in front or behind the retina, or at times at the both sides.
Symptoms of Astigmatism
Every problem that is existing is usually known or detected by some things or actions; these things or actions that take place are called symptoms. On the other hand, for one to know that astigmatism has set in, below are the symptoms:
- Blurred vision to some degree
- Distorted vision to some degree
- Eye strain
- Headaches after prolonged reading
What are the causes of Astigmatism?
Every kind of vision problem does not just start existing; it is usually caused by something. In the case of astigmatism, it is normally caused by an erratically shaped cornea. The shape of a cornea is usually like a baseball – whenever the cornea has the shape of a football with one of the meridians being extensively more curved than the one at right angle to it instead of that of a baseball, it is then said that astigmatism has set in.
Another cause of astigmatism is the shape of the lens inside the eye; but not the major cause of it. This cause is known as Lenticular astigmatism as a means of differentiating it from the usual corneal astigmatism.
The various types of Astigmatism
There are three basic or main types of astigmatism:
- Myopic astigmatism. This kind of astigmatism occurs when one or the both principal/major meridians of the eye are short-sighted or nearsighted. Once the both meridians become nearsighted, their differing degree becomes myopic.
- Hyperopic astigmatism. Like the name sounds, it is the opposite of myopic astigmatism. This one occurs when the both major meridians are farsighted. Their differing degree will also become hyperopic.
- Mixed astigmatism. This type of astigmatism occurs when one of the major meridians is farsighted and the other is nearsighted.
In classification of astigmatism, we also have regular and irregular astigmatism. The major meridians are usually 90 degrees apart in regular astigmatism, while the major meridians are not usually perpendicular in irregular astigmatism.
Irregular astigmatism can be caused by:
- Eye injury that has caused scar on the cornea
- Some eye surgery
- Keratoconus, usually a disease that causes the cornea to gradually grow thinner