Why do sunglasses have rainbows
The rainbow in sunglasses is a normal phenomenon, which is mainly due to the design principle of the polarizer. Polarizers use special filter materials to reduce light reflection and thus achieve the purpose of reducing glare. When the polarizer filters out the reflected light in certain directions, the color of the surrounding objects may change, resulting in a rainbow. This phenomenon is particularly evident in certain environments, such as water or snow. 12
Polarizers are one of the commonly used types of sunglasses that can effectively reduce glare and protect your eyes. Generally speaking, the polarizer rainbow will not cause obvious harm to the human body. If we see a rainbow in the process of driving with a polarizer, this is a normal phenomenon, do not panic, indicating that your polarizer is a real polarizer.
In addition, sunlight is absorbed or reflected in many directions. Sunlight reflected off a horizontal surface, such as land, water, or a car hood, usually bounces back horizontally, creating an intense glare. Regular sunglasses provide basic protection against vertical and horizontal UV rays, but they do not reduce glare from anti-horizontal rays. Polarizing glasses have a built-in filter that allows only vertical light to pass through and almost completely blocks horizontal light to eliminate glare. The car film is polarized either vertically (reducing road glare) or horizontally (reducing building/car side glare). When you place another polarizing filter between the current polarized light and the eye, it acts like a prism, resulting in a rainbow halo phenomenon.
