Advantages of resin polarizer:
1. Light weight.
2. Not easy to break: In case the lens is broken, not only will there be less fragmentation, but also less sharp, which can minimize the eyeball and face injuries.
3. Can be dyed: The resin lens is easy to dye, and can be appropriately matched with clothing and fashion.
4. Can block ultraviolet rays: almost completely block ultraviolet rays below 350mm, the effect is far better than glass lenses.
5. Strong anti-fog: Because the thermal conductivity of resin lenses is lower than that of glass, it is not easy to be blurred due to steam and hot water. Even if it is blurred, it will be very Fading soon.
6. Can prevent dents: Generally, high-heat and small-volume substances are likely to cause dents and spots on the optical lens, but if they touch the resin lens, they will automatically bounce. Open, will not cause any marks on the surface of the lens.
7. The surface reflection of the resin lens is lower than that of ordinary glass, and it is also less glaring.
8. The resin bifocal lens has no chromatic aberration. This is due to the integral structure of the resin bifocal lens, so there is less chromatic aberration than the fused glass bifocal lens.
9. The resin lens has a wide range of resistance to chemicals and solvents. Almost all household solvents and chemicals will not affect or damage it.
Disadvantages of resin polarizer
1. Easy to scratch: The scratch resistance of resin lens is worse than glass lens, but It can be improved by surface hardening treatment, but the effect is limited.
2. Optical lenses are prone to deformation when framed: This is because the density of plastic lenses is lower than that of glass lenses.
3. Not resistant to high temperature: Although the resin is a thermosetting material, once the multilayer film is coated, the surface of the multilayer film may crack due to high temperature.
According to the optical function of the lens:
1. Bifocal lens:
Bifocal lens is mainly used for presbyopia correction, providing presbyopic glasses with both near-use and far-use clarity on a pair of glasses vision. The bifocal lens can be divided into two independent areas. The upper part of the lens provides clear distance vision, and the lower part provides clear near vision. The two areas of the bifocal lens respectively provide different refractive powers, and the difference between the two different refractive powers is the reading near addition, which compensates the adjustment required by the focusing lens for reading by the presbyopic person.
Bifocals can be divided into flat-top bifocals and first-line bifocals. Generally, flat-top bifocals are more likely to be used. They only have a small area at the bottom of the lens for near-point work. As for the periphery and upper part of the lens, they are used to look far away and provide a good peripheral vision. The traditional bifocal lens is a first-line bifocal lens. The lens is divided into upper and lower parts in the middle, that is, all the less than half of the lens is used as the near point distance. They provide a relatively wide near point field of view, aiming at longer time and near point. Workers have better results.
2. Three-lens lens:
If the wearer needs different correction prescriptions for distance and near vision, two pairs of glasses can be combined into a pair of bifocal aspheric lenses. However, as the degree of presbyopia deepens, the near addition is also increasing to compensate for the decline in accommodation. When a bifocal wearer cannot obtain clear enough mid-distance vision beyond the near point regardless of whether he passes through the far vision zone or the near vision zone, then an additional amount that can provide middle-distance vision is needed to make the lens by It consists of three areas containing different prescriptions. This is the three light mirror.
The three areas of the tri-optical mirror are used for near, middle, and far distances, called the near, middle, and far vision (or reading area).
3. Progressive lens:
Progressive lens is a lens specially designed for people with presbyopia. It starts from the far-use area of u200bu200bthe lens and goes through the gradient in the middle (or the gradual zone) to the near In the area of u200bu200buse, the refractive power gradually changes.