First, there are different categories of common lenses
First of all, distinguish from the material
1. Resin lenses
Resin is a kind of polymer compound that becomes soft and plastic in response to heat. The resin lens is a lens formed by chemical synthesis and processing of resin as raw materials. Resin lenses have obvious advantages. Lenses made of resin are light in weight and more comfortable to wear. And the resin lens has strong impact resistance, is not easy to break and is safer; In addition, resin lenses have good light transmission, easy to reprocess to meet special needs, and cheap, so it has become the mainstream lens on the market.
Disadvantages of resin lenses:
The surface wear resistance and chemical corrosion resistance of the resin lens are worse than that of glass, the surface is easy to scratch, and the water absorption is larger than that of glass, which can be improved by coating method. Fatal disadvantages are high coefficient of thermal expansion, poor thermal conductivity, low softening temperature, easy deformation and affect the optical performance with positioning can adjust the alignment of the title
2. Glass lenses
Advantages of glass lenses:
Glass lenses are lenses made of optical glass, the clarity is slightly higher than that of resin lenses, and there is a higher refractive index, often used for lens purposes of the highest refractive index of 1.9. And the surface hardness of the glass lens is high, and the lens is more resistant to scratch and wear than that of other materials.
Disadvantages of glass lenses:
Glass lenses due to material reasons of large weight, to a certain extent affect its wearing comfort, coupled with the glass lens itself fragile characteristics, especially with the improvement of resin lens production technology and technology, in recent years, the use of glass lenses less and less.
3. PC lenses
PC lens is also called "space film", the chemical name is polycarbonate (is a thermoplastic material), with strong, not easy to break, can effectively prevent the fragmentation of the lens during intense exercise, so it is also called safety film. At the same time, the PC lens is light in weight and has good anti-ultraviolet performance. Therefore, PC lenses are mainly used in sunglasses and sports glasses.
Disadvantages of PC lens:
The surface of PC lenses is easy to scratch, and the price is high, the processing is troublesome, and the dispersion control is not ideal, so PC lenses are only sold in a small number on the market.
4. Nylon lenses
The main material of choice for nylon lenses is TROGAMIDCX - special transparent polyamide (commonly known as memory nylon), which is mostly used in sports brand sunglasses and high-quality sunglasses. Nylon lenses have high elasticity and excellent optical quality, strong impact resistance, very light weight, only about one-tenth the weight of the same volume of glass, only half the weight of traditional resin lenses.
Disadvantages of nylon lenses: nylon lenses have poor wear resistance and high production costs
5.AC lenses
PC lens and AC lens are resin lenses, but their process is different, the difference is that the former is harder, the latter is softer. AC lens is also called acrylic lens, with excellent strength and toughness characteristics, light weight, extremely high perspective, good anti-fog.
Disadvantages of AC lens:
AC lens is a kind of resin lens, the shortcomings are also high coefficient of thermal expansion, poor thermal conductivity, low softening temperature, easy to deformation and affect the optical performance.
6. Polarized lenses
The polarized lens is composed of multi-layer resin lenses, which can filter the interference of irregular light and avoid the occurrence of blinding and dazzling phenomena. Globally recognized as the most suitable for driving lenses, generally used in sunglasses, is a car owners and fishing enthusiasts must be equipped.
Disadvantages of polarized lenses:
If the arc bend of the lens itself cannot be in the optical standard refractive state, the polarization effect is weakened, affecting the authenticity of the image, and the durability is poor.