The application of the photochromic lenses
The photochromic lenses development up to now, has a huge commercial benefit. In many developed countries, the photochromic lenses for its healthy, convenient, beautiful, and many other advantages, is a high identity; At home, now there are a lot of people choose the high quality of photochromic lenses to protect your eyes, especially for people with nearsightedness or farsightedness, the quality of the photochromic lens is a better choice, and is suitable for wearing all the year round. Popular and developed countries of the world market in China is mainly resin color lenses, and in some countries such as Africa, South America, the glass color lenses still has certain market. Sales amount, the resin color lenses than glass color lenses, glass lenses due to its quality, Che easily broken, etc. , are slowly out of the mainstream market. With the continuous development of the optical industry, the application of photochromic lenses became more and more widely, obtained the high praise, has certain market competitiveness. As photochromic lens technology matures and improve, 1. 499, 1. 56, 1. 60 PCS, such as color lenses series have been growing, but the higher refractive index change color lenses will continue to update, including 1. 499 series of color lens osmosis mainly adopts surface will change color dye penetrant, present application will be more and more small, at present, our country most varieties of photochromic lenses of 1. 56 color lenses, at the same time, on the basis of the original dark brown and gray, added some colorful color glasses. In Europe and the United States, Japan and other developed countries and regions, the color lenses the main varieties of the gray and brown two kinds. These two kinds of color lens most varieties of visible light refractive index can be above 50%, and common varieties of refractive index is 70%. Due to the development of science and human needs, now there are a lot of photochromic glass lens, can be divided into grey color, yellow or orange color, prevent retinal degeneration color, dark brown color, blue color, gradient discoloration, LCD discoloration. In gray color lenses can be divided into shallow grey, grey, dark grey and black ash, the lens is very comfortable to wear, particularly suitable for glaucoma, electro-optic inflammation, keratitis and old people see the light and eye disease patients to wear. Yellow, orange color lenses, composed of silicon oxide, boron oxide, lithium, potassium hydroxide, zirconium oxide, silver halide, alumina melt into the system, such as the lens is suitable for long-term asked workers wear outdoors, also applies to the retina patients wear. Prevent retinal degeneration color lenses for two cases: the first kind is suitable for cataracts and removal of crystal and light to retinitis patients wearing the color of the lens, this lens can be completely blocked 440 pa these harmful rays; The second is suitable for retinitis pigmentation disorder patients use the color of the lens, it can tackle below 550, a ray. Not using ultraviolet light, about 25%, visible light transmittance of the ultraviolet light discoloration, visible light transmittance is less than the I/o %. Tan BianSeJing composition have silica, alumina and boron oxide, silver halide, etc. , at the same time also to join colorants such as cobalt, nickel and manganese. The original lens light transmittance about 85%, change color after the transmittance of 30 9 'or so. There is a dark brown color lenses, is in the basic glass added a small amount of palladium alloy, its color is due to the silver halide crystals containing or palladium alloy in surface sediment particles and discoloration. Blue color lenses is mainly composed of silica, aluminum hydroxide, boric acid, zirconium oxide, silver nitrate and cobalt oxide, cerium oxide and nickel oxide additives, such as the base of color is pure blue, after the ultraviolet irradiation is a dark blue or blue gray, the lens fading fast, can absorb 380 ~ 400 nm uv, wearing the blue color lenses, easy to eliminate eye fatigue. Gradient glasses, also called gradient BianSeJing, after exposure to uv or short-wave visible light, lens from top to bottom to present from deep to shallow color, the light transmittance is gradient distribution. The LCD color lenses particularly suitable for welding, welding, bus driver and glaucoma patients wear with light. Liquid crystal is a kind of organic compounds, this kind of lens discoloration speed is faster, the light changes color can quickly adapt to the outside world. At present, there are many new photochromic lens material, PVK color piece is a new type of silver halide image recording materials, it is composed of polyethylene carbazole, four bromide and other organic compounds and carbon fuel without basement of a photosensitive color material, after 360 ~ 450 t-shirts of uv exposure, fixing, fuel can obtain a variety of colors. PVK color piece of main technical indexes, 3000 lines of resolution to/Imn, etc. Complex photochromic resin lens is a kind of brand-new color lenses, it includes: the main purpose of vision correction and shading and mirror, for protective goggles, as a fashion, as the car driving glasses lens. Production technology of compound photochromic lenses is the first thing to produce the corresponding specifications of the base resin varieties with lenses, can choose different resin monomer material. Second is to make good base resin lens processing, using the surface composite design method. Is to allocate after good photochromic resin lens material, mould and injection prepared between the lens, then the corresponding heat curing, demoulding, cleaning, secondary curing, etc. , with reasonable shape of the product.