Astigmatism is a form of refractive error in the eye that is related to the curvature of the cornea. Some people's eyes have a curved curvature in a certain angle region, while other angle regions are flatter. The cause of astigmatism is that the inflection rate of each meridian of the cornea is inconsistent due to uneven thickness of the cornea or uneven curvature of the cornea, so that the rays passing through these meridians cannot be gathered in the same focal point, and the rays cannot be accurately focused on the retina. The formation of a clear object image is called astigmatism. The cause of astigmatism is complicated. From an objective point of view, basically divided into the following three situations: (1) In the first case, patients with eye diseases often suffer from unbalanced elasticity of the suspensory ligament of the eye due to frequent reading of books or watching television, resulting in inconsistent overall curvature of the intraocular lens, and the formation of myopic astigmatism. (2) The second condition is due to neonatal dysphagia in the eye and formation of intraocular lens concave and convex state. The overall curvature of "concavity" is inconsistent, resulting in simple hyperopic astigmatism or recurrent hyperopia astigmatism eye. In general, this type of astigmatic axis is 90° and it occupies a certain proportion of preschool children. With the increase of age, the development of the eyeball, and the increase in the number of eyes with close distances, the overall curvature of the "concavity" began to change. There are a few cases of myopic astigmatism caused by farsighted astigmatism. At this time, the astigmatic axis position is 180°. (3) The third situation is due to the increase in the size of the intraocular regulatory tissue with age, the hardened lens, the weakened elasticity of the suspensory ligament and the lens, causing the lens surface to be concave and convex, and the "concavity" as a whole is curved. Degree of inconsistency, resulting in the formation of simple simple presbyopic astigmatism or recurrent hyperopia astigmatism. In general, this type of hyperopic astigmatic axial position is 180°, and this phenomenon holds a large proportion among the elderly. prevention 1. It is best to do the first full eye examination when you are 3 to 4 years old, and to have regular eye examinations 1 or 2 times in the following year. Instruct young children to develop good hygienic habits. Do not casually touch the eyes with hands or their articles to avoid eye infections. When reading a book, the light should be sufficient, and the light should best come from the left rear; reading posture should be correct and maintain a distance between 30 cm and 40 cm. 2. The font should be clear when selecting the reading material. It should not be too small. 3. Watch TV must be 5 to 7 times the diagonal of the TV screen. Continuous reading of books does not exceed one hour. Glasses must be checked by a physician. Blood Pressure Transducer,blood pressure monitor,blood pressure machine,blood pressure monitor price,blood pressure Anesthesia Medical Co., Ltd. , https://www.jssinoanesthesia.com