It is called astigmatism to a disorder of the view that occurs when the crystalline and the cornea they have one irregular curvature on its surface. This results in a different refraction between the ocular meridians, making precise focusing impossible.
It should be remembered that the light focused on the retina it passes through the cornea, which functions like a lens. If the surface of the cornea does not have a regular and symmetrical curvature, astigmatism is generated. Curvature irregularity may also appear in the crystalline (the ocular structure behind the iris and in front of the vitreous humor, which acts like a biconvex lens).
Astigmatism is usually congenital: already suffered from the moment of birth. In milder cases, it may not manifest or generate symptom. In contrast, when astigmatism is marked, the person sees the objects distorted and blurred. Because the eye seeks to reverse the effect, it generates an overexertion in the muscles that can cause dizziness Y headache.
To treat astigmatism, which usually occurs alongside the myopia (a disorder that occurs when light rays arriving from a considerable distance establish focus in a site anterior to the retina), a surgical intervention with To be, to the use of glasses (glasses) with cylindrical lenses or to the use of contact lenses.
In addition to all the above, we cannot ignore another series of interesting data about astigmatism, such as the following:
-It usually appears early. And Hispanic and Asian children are considered to be more likely to suffer from it.
-It is possible to diagnose through one of the routine tests that are carried out in order to know the state of sight.
-It must be established that it is believed that around 26% of the population has this refractive defect. Moreover, it is even established that approximately 80% of those who have myopia also have the aforementioned.
-Contact lenses are the main tool used to carry out the “fight” against astigmatism. However, we have to indicate that there are those who prefer to opt for the use of surgery. In this case, it should be known that up to six diopters are operable with this mechanism.
It is important to mention that astigmatism can be classified as high, half or under and that can be defined as irregular or regular according to the arrangement of the main meridians. In the case of regular astigmatism, a distinction is made between simple astigmatism (simple hyperopic or simple myopic) or compound (compound hyperopic, compound myopic or mixed). There is also the oblique astigmatism, the reverse astigmatism and the direct astigmatism according to how the refraction.
Although we have mentioned many types of astigmatism, the usual thing is that three different classes are considered:
-The myopic, which occurs when one or both meridians of the eye tend to focus as myopic.
-The hyperopic, which takes place at the moment in which one or both of the aforementioned meridians proceed to focus as hyperopics.
-Mixed astigmatism, which is the type that is characterized by the fact that one of the meridians proceeds to focus as myopic and the other as hyperopic.