Among the many short-sighted people, there are a large number of patients with high myopia, high myopia of these patients at the time of purchase of the lens, it is necessary to consider the aesthetics of wear after, but also focus on the role of eye protection. So patients with high myopia should choose which lens it? Moon glasses remind you that patients with high myopia consider the following aspects when selecting lenses:

(1) lens material:

Lens materials are mainly glass, resin film and PC sheet (polycarbonate sheet) three. The main drawback of heavy glass lenses are lenses, especially in high myopia film, resulting in glasses on bridge of the nose and ear pressure patients increased significantly, wearing glasses often can not be tolerated. The latter two because of its light texture, plasticity and other characteristics, has been widely used in recent years, accounting for the absolute share of the lens market. High myopia sheet to select the latter two is appropriate.

(2) Refractive index:

It refers to the refractive index of the lens of the light turns ability, is the main parameters of the lens thickness. The refractive index of resin lenses currently on the market is generally between 1.49-1.74, the higher the refractive index of the lens is thinner than 1.60 called thin lenses.

(3) aspherical lens

High myopia should choose aspherical design of the lens. Aspherical lens having a specific centrifugal bits, from the center to the edge of the lens flattens gradually reduce the curvature, thereby reducing the edge too strong refraction and astigmatism edge. So aspherical lens than ordinary lenses under the same refractive thin 10% -30%, and the non-spherical lens spherical lens aberration rather only 1/5. Therefore, depending on the material nature aspherical lens, zoom uniform deformation.