What are the best companies producing lenses in the country?

There are three major brands from the international market, Essilor, TAG Heuer and Zeiss. The quality is very good but the price is also very expensive. From the domestic manufacturers of lenses, the good ones are Wanxin, Mingyue, Zunlong and Asia. Nowadays, with the merger and acquisition boom of Essilor, many leading companies have been integrated by Essilor. Zunlong and Asia, the top three companies of resin lenses in China, have also strategically cooperated with Essilor and set up Uli Optical Ltd. Specialized in optical products, Uli Optical is a professional company integrating research, production and sales, after many years of lens production and manufacturing. At present, U-Light has 1000 employees, 23 sets of coating machines, 5 sets of automatic hardening and cleaning equipment, 6 sets of automatic mold cleaning machine production line and one set of Kerben garage equipment from the United States. The company mainly produces 1.56 spherical, aspherical, 1.56 tea, gray aspherical, 1.60 MR-8, 1.67 MR-7 aspherical and other kinds of old light, old scattered and difficult garage film. With the technical support of Essilor Group, U-Lead will develop higher level products to meet the market demand for high-end products as well as to standardize in all aspects. With the tenet of "concentrating on the optical field", Uli Optical has passed the national QS mandatory certification, ISO9001 international quality system, EU CE safety and other certificates, and actively advocates the practice of modernized enterprise business philosophy, people-oriented, positive and enterprising, with first-class products, sincere service to provide better and better products for the consumers, in order to achieve the goal of a better and better optical industry. With the first-class products and sincere service, we provide consumers with better and better products, and make constant efforts to realize a more brilliant tomorrow in the eyeglasses industry.

:Classification of lenses

1, glass lenses

Glass lenses, with more scratch-resistant properties than other materials, but relatively heavy weight is also heavy, its refractive index is relatively high: ordinary piece of 1.523 (white, gray, tea), ultra-thin piece of 1.7 (red, white), 1.8 (red, white, purple), 1.9 (red, white) up to 2.0. Up to 2.0, but the highest refractive index currently used for eyeglass lenses is 1.9. The main raw material for glass lenses is optical glass. Its refractive index is higher than that of _fashionable lenses, so glass lenses are thinner than resin lenses for the same prescription. Glass lenses have better light transmission and mechanical and chemical properties, constant refractive index, stable physical and chemical properties. There is no color of the lens called optical white (clear optical lens), tinted piece of the pink piece called Cruxite lens (Cruxite optical lens), in the incandescent lamp was light purple-red, in the fluorescent lamp was light greenish-blue, called the Kes lens (Croo kes optical lens), Kes lens can absorb ultraviolet rays, on the bright light has a slightly Croo kes optical lens can absorb ultraviolet rays and has a slight absorption effect on bright light. Croo kes optical lens has only one manufacturer in China.

Glass lenses have superior optical properties, are not easily scratched, and have a high refractive index. The higher the refractive index, the thinner the lens. However, glass is fragile and the material is heavy, so when choosing frames, you should try to choose smaller frames so as to reduce the weight of the lenses and ensure the comfort of wearing them.

2, resin lenses

Resin is a kind of secretion from many kinds of plants, especially the hydrocarbons (_记饣物)of cedar plants. Because of its special chemical structure and can be used as a latex paint and adhesive and is valued. It is a mixture of many kinds of _latte swelling plating compounds, so it has different melting points. Resin can be categorized into two types: natural resin and synthetic resin. There are many kinds of resins, which are widely used in people's light and heavy industries, and can be seen in daily life, such as plastics, fashionable glasses, paints, etc. Resin lenses are made of resin as raw material. Resin lenses are lenses that are synthesized and polished using resin as the raw material for chemical processing.

3, space lenses

Space lenses are the most impact resistant lenses in the world at present, which can effectively prevent the shattering of the lenses during intense exercise, and the impact resistance is 10 times that of the ordinary resin lenses, and 60 times that of the glass lenses;

4, special lenses

In 1907, Owen Aves put forward for the first time the idea of progressive multifocal lenses, which marked a new type of special lenses, and the first time that a new type of special lenses were introduced, which was the first time in the world. It marked the birth of a new concept of special lenses for vision correction. The design of these specialty lenses was inspired by the shape of an elephant's trunk. By increasing the curvature of the front surface of the lens continuously from top to bottom, the refractive power changes accordingly, i.e., the refractive power increases gradually and continuously from the distal zone, which is located in the upper part of the lens, until the desired near refraction is reached in the near zone, which is located in the bottom part of the lens.