We are concerned about the quality of the optical lens and the design of the lens. We not only require high-quality glasses, but also hope that our own glasses have a unique design and increase their charm. The lens design mainly has the following aspects:

　　(1), aspherical lens: traditional spherical lens inevitably has the visual defect of spherical aberration in optics. The base curve of the non-spherical lens is flatter, lighter, and looks more natural and beautiful. In the case of high refractive power, the deformation of the glasses can be reduced. For consumers with high vision, it may be more appropriate to choose aspheric lenses.

　　 (2), asymmetric design: it is mainly aimed at customers with special requirements. In order to make binocular vision more comfortable, the wearer may require the lens to be as clear when looking at near objects and far objects. This optical lens puts forward many requirements on the design of the lens. Progressive lens is the abbreviation of progressive multifocal lens. The fitting of progressive lens must provide prescriptions for both eyes. Then, the designer uses the upper and lower width of the lens to design the upper part of the lens to be the luminosity for distance use. The half part is designed for near-use luminosity, and the upper and lower parts are designed as a continuous light addition. Progressive films allow consumers to have a clear vision from far to near.

　　 (3). Hard and soft design: For lens designers, define a new There are usually two ways for progressive lenses: ① Use a short, rapid progressive design, but this will accumulate a lot of distortion on the periphery of the lens, forming a rigid design. ②Using a long, slow gradual design to spread the distortion to the entire lens to form a soft design. Optical lens

　　 In fact, only a multi-layer design that combines the above two can form the best effect.

　　 (4), multiple designs: a single-design lens, it seems a little more than able to deal with multiple eye problems, such as when presbyopia and myopia occur at the same time . The multi-designed lens can adapt to the needs of different customers to meet the visual requirements of different wearers and ensure that each customer can wear it comfortably.

　　(5), Polarized lens: The design of polarized lens can protect people from reflected light, and can enhance the outdoor visual contrast. Especially when driving, polarized lenses can protect the wearer's eyes. Also, most dyed sunglasses use polarized lenses.

　　(6), Multi-focus design: The design of double beam, triple beam and progressive lens all have a common focus lens, that is, the principle of small range is used. In the same lens, the near-use area and the far-use area are divided, and these areas are connected in a large area. However, the above three are different in the division of the lens spherical surface.

　　 Bifocal lenses are mainly used for hyperopia correction. The classic bifocal lens design makes the wearer Can see far and near at the same time, wide field of vision. It has a better effect on workers near the point for a long time, such as architects, accountants, artists, etc.

　　Trifocal lenses are mainly for those who need middle-distance vision, such as those who often work in front of computers or cash registers.

　　 Progressive multifocal lenses use gradually progressive refractive power instead of instantaneous change of power. This design can avoid the phenomenon of 'image jump'. For example, in the aspheric lens in the supermarket, you can easily go through the progressive multifocal lens and check the shopping list carefully, and at the same time, you can easily find the product you want on the shelf. But the initial stage of wearing progressive lenses requires some training.

The main characteristics of 　　 spectacle lenses are optical properties, mechanical and thermal properties, electrical properties and chemical properties.

　　(一)Optical properties

　　Optical properties refer to the properties of calculating refractive action and controlling optical performance.

　　(2) Mechanical and thermal properties

　　 Mechanical and thermal properties refer to the characteristics of the lens shape and resistance to deformation.

　　(三)Electrical properties

　　Electrical properties refer to the characteristics of electromagnetic waves and electric effects of materials.

　　(四)Chemical properties

　　Chemical properties refer to the understanding of the corresponding changes of materials through chemical substances in contact with the outside world characteristic.