What are astigmatism lenses?_lens knowledge

Nearsightedness, farsightedness, and astigmatism are all refractive errors and must be corrected by lenses. Most people have a little astigmatism, many of which are caused by defects in the eyeball, and they need to wear a certain degree of astigmatism lens to correct it. Below, the editor of OULE glasses net will take you to learn more about some related knowledge of astigmatism lenses. People suffering from astigmatism, if they are not properly cared for and corrected, will not only cause vision loss, but also cause visual fatigue and accelerate the development of myopia. Therefore, in real life, it is very important to correct astigmatism. The so-called astigmatism is not the same as myopia and hyperopia. It changes unevenly, that is, on the same lens, the irregularities on the surface cause the parallel light rays entering the eye to be unable to converge at one point. Therefore, There are three main positioning methods when wearing astigmatism lenses for correction. 1. Dynamic positioning method: The lens adopts the method of thinning the central thickness on both sides, and the tension of the upper and lower eyelids is used to fix the lens, so that the position of the lens is in a dynamic and stable state, so that the movement of miscellaneous eyes can change the vision and correct astigmatism. However, the effect of this method varies from person to person, and the effect of correction for different groups of people is different. 2. The principle of symmetrical and balanced positioning: that is, to use the power of the two sides outside the optical zone to maintain the balance and stability of the lens, so in the design of the lens, the periphery is thin and uniform, so that the lens has a good effect of itching, and it is more comfortable to wear. The effect of positioning stability is also relatively reliable. 3. Prism positioning method: This is a simpler way to wear astigmatism lenses, mainly on the lens, design a bottom-down prism to stabilize the astigmatism lens, plus the pressure of the upper eyelid, so as to keep the lens on the eye Rotation, the correction effect is both effective and convenient. However, this positioning method will cause the thickness of the lens to be different, so the wearer will have a foreign body sensation or an uncomfortable wearing experience. As the name suggests, astigmatism lenses are high-tech medical products used to correct astigmatism. They can not only effectively remove astigmatism inside the eyeball, but also have a great effect on controlling the development of vision. Therefore, it is very necessary for people suffering from astigmatism to wear astigmatism lenses.