Is the temple of crystal glasses folded or not?

Crystal sunglasses refer to sunglasses with Swarovski crystals embedded in the frame, which is not helpful for optical performance. Of course, there are also glasses with crystal grinding lenses, but there are two advantages. First, it is expensive. Second, the legendary jade magnetic field can adjust Feng Shui and improve the body. This should be the so-called reason to protect your eyes.

In fact, the optical performance of crystal is far less than that of optical glass and optical resin. Crystal inevitably contains impurities, and its transmittance is far less than that of optical glass and resin. Polarized sunglasses are based on sunglasses with a polarizing film. The function of polarizing film is to filter polarized light. In detail, you need to learn optical knowledge, but in simple terms, it can be used to filter some reflections. For example, look at things in the glass window, because the glass reflects light, you can't see clearly. A polarizer can filter out reflections and directly see what's inside. When driving, the reflection of the road will also affect the line of sight. Polarizers can also be filtered out, so they are especially suitable for drivers.

However, it can't filter out all the reflections, only the reflections falling into the incident angle of about 30 degrees, and it has a great disadvantage that the LCD screen may be seriously color-cast or even invisible, because the light of the LCD screen is polarized light, and it will be completely filtered out if the angle is appropriate. As for ultraviolet light, it is not a problem at all. Almost all sunglasses have the function of worrying about ultraviolet rays.