Causes of Astigmatism
Are nearsightedness and astigmatism the same? How is astigmatism caused? Will the degree of astigmatism gradually deepen? How is astigmatism treated? Will astigmatism go away on its own? Need to wear glasses all the time?
In fact, the cause of astigmatism is due to the uneven surface curvature of the cornea and lens, which leads to different focal lengths of the eyeball on different axes, resulting in more than one focal point, and the image becomes blurred. Under normal circumstances, the curvature of the corneal refraction interface is average and spherical. The following will introduce the causes and treatment of astigmatism in detail, hoping to clear up the confusion for readers.
Causes of Astigmatism The eye is like a camera, and the cornea is like the lens of the camera. The image is focused through the refraction of the cornea to form a clear picture on the retina, just as the camera lens focuses and projects the scene on the film. Under normal circumstances, the surface of the cornea (that is, the refracting interface of the eyeball) is spherical, like a ball, and the surface curvature of different sections is exactly the same so that the image can be accurately and clearly projected onto the retina.
For patients with astigmatism, the curvature of their corneal refraction interface is uneven, and it is rugby-shaped. For example, the curvature of the transverse section is relatively flat, and the transverse curvature becomes flat. Because it is too narrow, the image falls behind the retina. The deviation between the two radians makes the refractive power different, and the image cannot be clearly focused, which will form astigmatism.
Astigmatism problems are common
Astigmatism is prevalent. In fact, more than 9 adults have astigmatism in varying degrees, and about 10-20% of them have astigmatism greater than 100 degrees. And astigmatism is mainly congenital, and generally has nothing to do with reading a book for a long time, using a computer, etc.
The degree of astigmatism is also relatively stable and generally does not deepen with time and age like myopia. However, if there is astigmatism caused by certain eye diseases, such as keratoconus, the degree of astigmatism may deepen.
The symptom of astigmatism is that you can’t see far and near clearly. The deeper the degree of astigmatism, the more blurred the far and near objects will be, and the near objects will even become larger. Blur, headache, dizziness, and other phenomena.
Astigmatism in children needs to be corrected in time
As children are in the stage of visual development, if astigmatism exceeds 100 degrees without correction, blurred vision will not be corrected for a long time, and the brain will not be able to obtain clear images, which may lead to amblyopia or rapid progression of myopia, which will affect vision. The deeper the degree of astigmatism, the greater the risk of affecting vision.
Symptoms of astigmatism mainly include blurred vision, near objects, and distant objects will appear blurred, the light seems to be scattered, some people will feel that the images they see have double images, and the situation can become blurred at night. more serious.
The deeper the degree of astigmatism, the more blurred the far and near scenes will be. In severe cases, the image may even be distorted. If the astigmatism is not corrected in time and accurately, it will cause visual fatigue and a series of related symptoms, such as dizziness and headache.
How to correct mild astigmatism?
How to correct mild astigmatism? Generally, there are no simple and mild symptoms of vision problems, and there is no need to wear glasses for correction. If the degree of astigmatism exceeds 100 degrees, correction should be considered, and the correction methods for astigmatism are divided into non-surgical and surgical methods.
Non-surgical methods include wearing frames glasses or contact lenses, both of which are more commonly used. Contact lenses can choose to use soft contact lenses or hard contact lenses with the function of correcting astigmatism, but the chance of causing complications such as corneal hypoxia is higher than that of frame glasses. Of course, it is acceptable to choose contact lenses with high overall safety plus regular care.
However, for severe astigmatism patients, the image effect obtained through glasses may not be ideal, and contact lenses also have risks. On the one hand, compliance is poor, and on the other hand, cleaning and nursing work may not be carried out in time. If these patients are not effective in correcting astigmatism with glasses, they need to consider surgical methods to help solve it.
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