How to distinguish glass lens from resin lens?

1. Different raw materials
The main raw material of glass lens is optical glass; Resin lens is an organic material with a polymer chain structure inside, which is connected to form a three-dimensional network structure. The intermolecular structure is relatively loose, and there is space between the molecular chains that can produce relative displacement.

2. Different hardness
Glass lens, with more scratch resistance than other materials, is not easy to scratch; The surface hardness of the resin lens is lower than that of the glass, and it is easy to be scratched by hard objects, so it needs to be hardened. The hardened material is silicon dioxide, but the hardness can never reach the hardness of the glass, so the wearer should pay attention to the maintenance of the lens;

3. Different refractive index
The refractive index of glass lens is higher than that of resin lens, so under the same degree, the glass lens is thinner than resin lens. The glass lens has good transmittance and mechanochemical properties, constant refractive index and stable physical and chemical properties.
The refractive index of the resin lens is moderate. The common CR-39 propylene glycol carbonate has a refractive index of 1.497-1.504. At present, the resin lens sold on the glasses market has the highest refractive index, which can reach 1.67. Now, there are resin lenses with a refractive index of 1.74.

4. Others
The main raw material of glass lens is optical glass. Its refractive index is higher than the resin lens, so the glass lens is thinner than the resin lens at the same degree. The glass lens has good transmittance and mechanochemical properties, constant refractive index and stable physical and chemical properties. The lens without color is called optical white (white), and the pink lens in the colored lens is called Croxel lens (red). Croxel lenses can absorb ultraviolet rays and slightly absorb strong light.

Resin is a kind of hydrocarbon (hydrocarbon) secretion from a variety of plants, especially conifers. Because of its special chemical structure and can be used as the latex paint and adhesive, it is valued. It is a mixture of various polymer compounds, so it has different melting points. Resin can be divided into natural resin and synthetic resin. There are many kinds of resins, which are widely used in people's light industry and heavy industry. They can also be seen in daily life, such as plastic, resin glasses, paint, etc. Resin lens is the lens after chemical processing and polishing with resin as raw material.