The Five Types of Lenses
As we know, the function of prescription glasses focuses on its lens. Different types lens have different functions. With the development of technology, lenses are endowed more and more functions. Generally speaking, lens can be roughly divided into five types — anti-reflective lens, color lens, tinted lens, polarizer lens and photo chromic lens. Each type has its own unique features.
reading glasses
Anti-reflective lens: on the surface of this lens is coated a thin layer of magnesium fluoride in order to prevent reflection by the strong light, and enable wears clearer scenery without the interference of strong light. To examine whether your cheap eyeglasses is the anti-reflective lens, you can let the eyeglasses directed at light source, if you can see purple reflective light, it can be said that the lens is really coated anti-reflective protective material.
Color lens: it is also called “stained lens”, that is, in the process of lens manufacture, lens is added some chemical substances, so that make lens present color in order to absorb lights with specific wavelengths. This is the most commonly used lens type in sunglasses.
Tinted lens: this type of lens presents a similar effect with color lens. The only difference between them is that they are made in different techniques. Tinted lens coats the color material on its surface. Well, the most well-known one is the “progressive color changing tinted lens”, which the color is dark in upward and light in downward. Commonly, a number of myopic sunglasses are adopted this lens type.
Polarizer lens: in order to filter the reflective sunlight from water, land or snow, some special coating materials are added in lens in vertical way. This kind of lens is called polarizer lens. Such type is most suitable for outdoor sports, such as marine activities, skiing and fishing.
Photo chromic lens: it is also referred to photosensitive lens. The lens is incorporated with the chemical substances of silver halide, so that allow the colorless and transparent lens turns into colorful lens under the sunshine, thus play a role of eye protection. Therefore, such kind of lens is appropriate to wear both indoor and outdoor.
Above is the general introduction of the five lens types. With the invention of television, computers and other electronic invention, they bring about more and more potential threat for eye health. Obviously, today more and more people have worn eyeglasses, so know more knowledge of it can help people to correctly choose and buy eyeglasses.
