Why Polarized Sunglasses Are More Comfortable And Softer Light Than Regular Sunglasses

The polarizing function of sunglasses can block the glare in the sun, which can protect the eyes from ultraviolet rays. It's all thanks to the metal powder filter mounts, which comb the messy light into the right light as it hits, so that the light entering the eye becomes softer.

Polarized sunglasses can selectively absorb the local bands that make up the sun's rays, because it uses very fine metal powders (iron, copper, nickel, etc.). In fact, when light hits the lens, the light is subtracted based on a process called "destructive intervention". That is, when certain wavelengths of light (in this case ultraviolet a, ultraviolet b, and sometimes infrared) pass through the lens, they cancel each other out on the inside of the lens, toward the eye. The stacking of light waves that make up light waves is not accidental: the crests of one wave merge with the troughs of adjacent waves, causing them to cancel each other out. The phenomenon of destructive interference depends on the index of refraction of the lens (that is, the level of deflection of light rays as they pass through different substances from the air), and also on the thickness of the lens.

Generally speaking, the thickness of the lens does not change much, and the refractive index of the lens varies according to the difference in chemical composition.

Polarized sunglasses provide another mechanism for eye care. The reflected light of the asphalt road is relatively special polarized light. The difference between this reflected light and the light coming directly from the sun or any artificial light source is a matter of order. Polarized light is composed of waves that vibrate all in one direction, while ordinary light is composed of waves that vibrate non-directionally. This is like a group of people walking around randomly and a group of soldiers marching at a uniform pace, forming a clear antithesis. Generally speaking, reflected light is an ordered light. Polarized lenses are especially effective at blocking this light because of its filtering properties. Such lenses only allow polarized waves that vibrate in a certain direction to pass through, as if "combing" the light. Regarding road reflection, the use of polarized sunglasses can reduce the transmission of light, because it does not allow light waves that vibrate parallel to the road to pass. In fact, the long molecules of the filter layer are oriented in the horizontal direction and are able to absorb the polarized light. In this way, most of the reflected light is eliminated, and the overall illumination of the surrounding polarized sunglasses environment is not reduced.

Finally, the lenses of polarized sunglasses can darken when the sun's rays hit. When the lighting faded, it became bright again. This is possible because the crystals of silver halide are at work. Under normal conditions, it enables the lens to maintain perfect transparency. Under the sunlight, the silver in the crystal is separated, and the free silver forms a small aggregate inside the lens. These small silver aggregates are criss-crossed, irregular blocks that don't transmit light, only absorb it, resulting in a darkening of the lens. Under the condition of light and dark, the crystal is restructured, and the lens returns to its bright state.