1: refractive index

Optical glass lenses according to the refractive index can be divided into crown glass (refractive index of 1.49 to 1.53) flint glass (refractive index of 1.60 to 1.9), the refractive index directly affects the thickness of the lens, that is, the higher the refractive index, The refractive index of the resin sheet is between 1.49 and 1.76.

2: dispersion coefficient

In the lens is usually applied to the dispersion coefficient, also known as the Abbe number! Abbe number is to measure the imaging accuracy of the lens! Abbe larger, the smaller dispersion, the higher the clarity, but when the higher the refractive index Time, Abbe number also will become low.

3: light penetration ratio

Light penetration ratio is to measure the clarity of the lens, that is, the higher the light through the ratio, depending on the more clear, but now the coating lens through the light can reach 98% or so, so this value in the selection of the lens when you can not have too care.

4: density

Said the direct point is the weight, the higher the density the heavier the weight of all the glass sheet density should be higher than the resin lens! And the higher the refractive index, the density also increases!

5: Chemical stability

The so-called chemical stability, refers to the lens in the processing and use of other chemical substances in the corrosion resistance, in the selection only need to check the surface of the lens mold, coating off, surface finish uneven and so on! Mirror within three months are quality problems!

According to the above description, in the choice of the lens, according to their own for the lens thickness, safety, wear resistance, try to choose low refractive index, high Abbe number, small density of resin or glass can be!