Absorptive filter, because the lens absorbs some light, it turns into heat and emits heat, especially infrared rays and other light with longer waves. The accumulation of heat makes the eyes feel very uncomfortable. If a reflective filter is used, this problem can be solved well.
If the surface of the lens is coated with a material film with a refractive index higher than that of the lens itself, it will increase the reflection of light and reduce the intensity of the transmitted light, so as to protect the eyes from strong light and harmful rays. hurt.
In actual work and life, in many cases, the absorption type and the reflection type are used in combination, that is, a layer of high reflection film is plated on the colored lens to make the filtering effect stronger, such as electric welding, chlorine arc welding, plasma cutting and other operators. Wearing glasses, you can use this method to solve.
The optical glass blank produced by the glass factory is processed into a glass sheet with a certain refractive power and shape after a series of grinding and polishing processes in the glasses factory, which is called an uncut lens. Preparing glasses is to select appropriate lenses for cutting, edging and other processes to make them conform to the shape of the frame, and then install the frame. Although the lenses are inspected, marked, etc. when they leave the factory, when preparing the glasses, the spectacleist should also perform the procedures of measuring, marking and inspecting the lenses so that each pair of glasses can accurately meet the prescription requirements.