If you know anything about eyeglass lenses, you may have heard the terminology – lens coating. But do you know that the color of the lens coating also has an impact on the function? Which color is better?
First, let’s understand what lens coating is. Coated lens is the use of optical film and vacuum new technology, coated with a certain thickness of single-layer or multi-layer optical film, so that the lens to obtain some new, originally do not have the excellent performance, in order to improve the ability of the lens to reflect the light, play a role in enhancing or reducing the role of the light through the lens light transmission increased to 98%.
The color of the first production of coated lenses is green, mainly to distinguish them from non-coated lenses. At 515 nm, the reflection gives an enhancement of about 2%, so that the contrast is there and the reflection is seen as a green film. This film layer is the standard reflection reduction film, which is currently good and old.
Relatively speaking, the green film layer is better in the effect of UV protection and relief of eye fatigue, and the light green color is not easy to be found on the lens, which is the common color of the lens coating layer at present.
Blue film lenses are very good in anti-radiation and anti-blue light performance, and can absorb more than 99% of blue light and radiation, creating a safe environment for you to use your eyes and giving you a wider field of vision.
But there are certain shortcomings of the blue film: the reflection of blue light is too big, about 10~15%. Such a lens, from the optical point of view, reduces the light transmission rate, and when there is light behind the person, there will be a strong reflection, especially the driver is more unsuitable for this kind of lens. There will be obvious blue ghosting or blue horizontal lamp tube-like reflections when driving at night.
Red film is to increase the reflectivity of the red part, i.e. in the area of 700~780 nanometers, to increase the amount of reflection, which also affects the light transmittance, but it is a little bit better than Orchid film, because we are not very sensitive to the red part. Gold film is to increase the amount of red and yellow reflection, also affects the light transmission. It is not in accordance with the principle of optical use, but just a kind of decorative effect.
At present, the above three films are common on the market, and there are several kinds of eyeglasses lens coating, which also have different advantages, roughly as follows:
1, Hardening film: increase the hardness of the lens surface, make it more wear-resistant.
2、Reflection reduction film: increase the transmittance of visible light and the performance of UV and radiation protection.
3、Anti-fouling film: due to the technical needs of the anti-reflection film, the inter-molecular gap between the film is large, and the surface of the lens is easy to hide dirt, while the anti-fouling film has small molecular particles and small inter-molecular gaps, which makes the surface of the lens more polished, and increases the functions of waterproofing, anti-fogging, anti-dust and other