What Do You Not Know Knowledge About Astigmatism?
How is astigmatism formed, can be deepened after adulthood? Astigmatism and myopia, although see thing is fuzzy, but the reason is different .
Everyone must be very clear to the cause of myopia formation, the eye axis is too long, the external parallel light passes the refractive system of the eye, the focus falls in front of the retina, making the image blurred. Astigmatism is mainly due to the cornea is not round, horizontal and vertical meridian curvature caused by the refractive error, parallel light will be focused in front and back of the retina, the phenomenon of "double shadow".
Normally there is only one focal point, but people with astigmatism have multiple focal points on the retina.
Astigmatism is mainly caused by the following reasons:
1.Genetic
Heredity is one of the main causes of astigmatism. According to clinical data statistics, the probability of astigmatism in children of either parent with astigmatism is much higher than the probability of astigmatism in offspring of normal parents.
2. Bad habits
Keep bad eye habits for a long time, such as lying down to read, often rubbing eyes, squinting eyes, easy to pressure the cornea, corneal shape change, and lead to astigmatism.
3. Disease
Astigmatism can also occur after cure of certain eye disease patients, such as keratoconus, corneal ulcer, keratitis, pterygium.
4. Trauma and surgery
When corneal injury occurs, and after partial eye surgery, it may cause keratoconus, and then produce astigmatism.
After birth, most babies have obvious astigmatism in the horizontal direction due to incomplete eyeball development, and astigmatism will decrease significantly after a few years of birth. With the increase of age, the corneal shape gradually changes from transverse ellipsoid in children to longitudinal ellipsoid in adults, and the horizontal astigmatism gradually disappears and becomes slight astigmatism in vertical direction.
Throughout life, most people have astigmatism in both eyes, but more or less the problem, within 50 degrees of astigmatism is normal.
Astigmatism, unlike nearsightedness, does not continue to deepen, but can remain stable or decrease slightly over a long period of time. When doing the vision test, if you find yourself with astigmatism, it is recommended to wear glasses to correct it.
Because on scientific research discovery, if astigmatism is not corrected in time, may cause myopia degree to deepen. Astigmatism may block optical cues leading to emmetropia and trigger the development of ametropia. There are animal experiments that support this theory. These animal studies found that, due to changes in eyeball growth caused by astigmatism, the myopic animals with uncorrected astigmatism showed greater myopia progression in the same time frame than the myopic animals with uncorrected astigmatism. There was a certain relationship between uncorrected astigmatism in young animals and the development of myopia in adolescence or early adulthood.
People with astigmatism are more likely to have vision loss and visual fatigue, and there is no timely correction of glasses, which may lead to further deepening of myopia, so regularly check the eyes and find astigmatism, it is necessary to timely correction of glasses .
