Lens is the main part for a pair of glasses. If the glasses are produced, the lens can not be changed any more. At the same time, eyes’ health depends on lens and the right ones suitable for eyes will reach the aim of improving eyesight. When choosing the glasses, choosing lens is the first step. Of course, there are many elements influencing the choice, such as the lifestyle, working environment, personality, some functions of lens and so on.
The Color of Lens
Students, doctors, artists and drivers should wear glasses with colorless lens. People in these kinds of fields have high demands for color and distance. If wearing colorful glasses, drivers can not control the distance change, which may cause some traffic accidents. As for the doctor, things will be worse. Patients’ lives then will be in danger just because of the improperly colorful lens. Even though colorful lens are in the day and more and more people begin to wear a pair of colorful glasses, colorful lens are not suitable for all myopia people. When choosing lens, you should think twice.
The Shape of Lens
Before deciding the shape of lens, choose the right glasses frame first. Generally speaking, the shape of lens is decided by the shape of the frame needing them. You’d better choose the frame allowing the lens of proper size. Too little lens are not the wise choice, though they are in vogue nowadays. Meanwhile, glasses with strange shapes of lens are popular with people, especially young people. Well, thanks to some fashionable designs, more classical glasses are produced. But for eyes health, glasses with traditional shape of lens should be considered first. After all, glasses are the tool for eyesight improvement first, besides the function as the ornament.
The Transmittance of Lens
Transmittance is also one of the important elements when choosing lens. To avoid the radiation from computer, lens with anti-radiation films are widely used in glasses. Colorless optical lens and aspheric thin lens also have good transmittance.
The Weight of Lens
The weight of lens has great relation with the material. Then the degree and shape are also relative aspects. The common materials for lens are glass and resin. Generally speaking, lens made from resin is much lighter and the weight is about half of that are made from glass. Compared to glass lens, resin lens has a lot of advantages. The most attractive one is that they are light, which decreases the pressure imposed on the nose and helix. And then its capacity of anti-force is better, several times of that made from glass. When there are some accidents, people with glasses having resin lens are much safer and there is no need to worry about damage for eyes. The cost is lower, too. If there is a model, thousands of lenses can be made and therefore time and cost for production is decreased greatly.
The Hardness of Lens
Lens made from glass are harder than the one made from resin. Resin lens are easy to be damaged, especially the surface. As for the surface, the capacity of anti-fiction and chemical resistance ability is worse. By the way, resin is inclined to absorb more water. Well, the above disadvantages can be overcome by adding platting to the surface.
The Strength of Lens
Resin lens is stronger than glass ones. This is an important reason why resin lenses are more and more used for glasses rather than glass ones. There is always news about people’s eyes being hurt by broken glass lens. Glasses are so near to eyes and if the lens is not strong enough, eyes are in danger all the time.
The Thickness of Lens
The thickness of lens is influenced by many elements, like material, degree, shape, refraction rate, etc. The higher the degree is, the thicker the lens is. But with the development of new material and producing process, lens are becoming thinner and smaller than before. After all, a pair of thick glasses will affect the appearance, to some extent.
Special Functions of Lens
Some lenses have special functions, such as lens against ultraviolet, ultra-red ray resistance, anti-deformation and so on. Glasses with special usage use such special lens. According to the need, you can choose some kinds of lens.
Do take care of your eyes in daily life. So choose the right lens for them.