Polycarbonate material brings thermoplastic materials back to the field of discount eyeglasses online lenses. Its optical properties are comparable to other lens materials, and it has excellent impact resistance. It is also known as a cosmic film, suitable for sports enthusiasts.

The performance of lens materials includes refractive index, dispersion, transmittance, and light absorption in optics. The physical properties include density (specific gravity), hardness, wear resistance, impact resistance, fracture resistance, and thermal deformation.

Chemical properties such as corrosion resistance and dyeability. The refractive index refers to the ratio of the propagation speed of light in air to the propagation speed of light in the lens. The refractive index is also used to measure the thickness of a lens to a certain extent. The larger the refractive index value, the thinner the discount eyeglasses online lens.

The sunlight seen by the human eye is polychromatic light, which is then transformed into ordered monochromatic light through a prism. This phenomenon is called dispersion.

The Abbe number is expressed as the reciprocal of the dispersion coefficient and can be used to measure the degree of light dispersion in a medium. The higher the Abbe number, the lower the dispersion, and the clearer the object can be seen through the lens.

Transmittance, also known as the light transmittance ratio, is an indicator that reflects the clarity of the visual object through a lens. The higher the transmittance, the clearer the view. (Related to the discount eyeglasses online material and coating of the lens)

Specific gravity refers to the ratio of the mass to the volume of a substance. The higher the density of lenses of the same volume, the heavier the lenses. Hardness is the ability of a material to resist local pressure from hard objects on its surface.