Glasses when sales staff will ask you to choose which Fake Oakleys Frogskins Sunglasses Cheap for Sale lens is non-spherical mirror or spherical mirror; and will come up with two kinds of lenses than let you see results, and then tell you aspheric compare welcome by everyone, then aspheric What are the advantages make it so popular? how do we identify aspherical it?
Full understanding of the advantages and aspherical lens identification methods
First, what is non-spherical mirror
The so-called non-spherical lens, refers to the front surface of the lens (ordinary aspherical lens) use of non-spherical design, which means that the curvature of the lens is not a fixed value. Such lenses will watch over conventional spherical lens outer thinner, that at the same luminosity and refractive index aspherical lens will thin more than 10%; while the vision presented by the lens will be greater.
Second, the advantage of aspheric
1 aspherical lens surface with high-tech design, by the scope of the center and the edge of the mirror and the light entering the eye are the same focal length, which makes the imaging light path lens acceptable range is large, light entering the eye more, Cheap Mac Cosmetics Makeup wholesale Outlet visual good effect.
2 aspherical lens center and periphery close to the same degree, to see objects no aberration.
3 conventional spherical lens above the center of prism degrees around; rather than spherical lenses are precision grinding, high temperature softening, leveling, surrounding the center of prism degree closer. For the same refractive index lenses, aspherical mirror thinner than the ball 17 percent, 10 percent lighter.
4, aspheric lens surface is flat, spherical lenses than ordinary wear to a more beautiful, comfortable and has become a fashion of many white-collar consumers.
5, can reduce or eliminate the nasty astigmatism (astigmatism), that is, away from the scene with the optical center and distortion, which is the Achilles heel of the spherical shape of the lens, this phenomenon is a positive change in the arc through aspheric urination shaped surface to overcome the road, be able to do with the eye away from the central part of the lens, and is still very clear, as the object of effect.
Three aspherical lens identification methods
1 use focimeter identification. Spherical Tiffany and Co Outlet lens vertex degree compared with the edge, the edge is less than negative vertex degree; positive vertex degree is less than or close to the edge. Rather than spherical lenses vertex compared with the edge of the degree, whether positive or negative film, spherical degree closer to the lower edge, and the closer to the higher degree cylinder edge.
2 naked eye observation. The same material, the same degree of spherical compared with non-spherical, aspherical lens flatter, thinner, depending on the material more realistic, more natural and comfortable. If the front of the tube watching the shape of the lens coating is generally spherical lens reflex tube relatively straight (except for high-diopter lens); rather than spherical lens surface due to various parts of different curvature, the curvature of the larger tube shape.
3 using the mirror of the table to identify. Same spherical curvature of the lens surface, rather than spherical lens surface curvature also vary due to the different parts. By measuring the results mirror of the table is very easy to identify.
Four aspherical lenses for the crowd
Thin aspherical lens, mirror edge difference can be corrected, with the naked eye to see objects is almost the same, more health care than spherical lenses. Suitable for a high number of persons, high astigmatism, contact lenses and glasses wearers and first alternate wearing Tiffany and Co Necklace Jewelry Outlet Store glasses and wearing large frame glasses. But not for those who are particularly sensitive to the eyes of those who require high vision, strabismus.