Quality sunglasses near me now are very effective “light conditioners”. Sunglasses can adjust external light, so that it is suitable for the human eye in the next part we will describe the various technologies used by sunglasses manufacturers to adjust light, in order to better understand these technologies, you must first understand some knowledge about light.


A light wave has a certain amount of electromagnetic energy, and the size of the wave is measured in wavelengths, which range from 400 to 700 nanometers for visible light. The energy of the light wave is inversely proportional to the wavelength, the shorter the wavelength, the higher the energy, in the visible light, the purple light energy is the largest, the red light energy is the least, and in the visible light spectrum is ultraviolet. In fact, natural light contains a lot of ultraviolet rays. Due to the high energy of ultraviolet light, ultraviolet light can cause damage to your cornea and retina. 


The measure of brightness or intensity of light is lumens. Indoors, for example, most artificial light has an intensity of 400 to 600 lumens. If in the sunny outdoors, the brightness will float in a wide range, the brightness of the shade is 1000 lumens, and places like highways and other large cement floors, the brightness is 6000 lumens, below the brightness of 3500 lumens, our eyes feel very comfortable, when the brightness of direct light or reflected light reaches 4000 lumens, The human eye begins to have difficulty receiving light. When we try to look hard at these very bright areas, we only see a white flash, which is glare. In order to reduce the discomfort caused by the large amount of light entering the eye, we begin to squint. Once the brightness reaches 10,000 lumens, your eyes begin to filter out the light completely because the light they receive is too strong. Being exposed to such strong light for too long can cause damage, leading to temporary or even permanent blindness. The light reflected by a large area of snow can be as bright as 12,000 lumens, and if we look directly at it without any protection, it will cause snow blindness. 


Visible light is the light that the human eye can detect, and the visible light we see from the sun looks colorless, which is what we often say white light. In fact, it is a mixture of multiple frequencies of colored light, in the visible spectrum of all colored light mixed into the light is colorless, that is, white.


There are two basic ways we can see color. One way is that an object itself emits light of a certain frequency, such as neon lights do, and the other way is that the object absorbs all other frequencies of light and reflects only a certain frequency of light, or reflects multiple frequencies of light, and these light waves mix and are perceived as one color of light. For example, painted objects are displayed in this way, for example, to see yellow light, one way is the object directly emits yellow frequency light, another way is to absorb the light in the blue part of the spectrum, reflect the red and green parts of the light, the two kinds of light mixed by the human eye perceived as yellow light.