Use classification
Sunglasses can generally be divided into three categories: sun-shading mirrors, light-colored sunglasses and special-purpose sunglasses.
The so-called sun-shading mirror, as the name suggests, is used for shading. People usually adjust the luminous flux by adjusting the size of their pupils in the sun. When the light intensity exceeds the adjustment ability of the human eyes, it will cause damage to the human eyes. Therefore, in outdoor venues, especially in summer, many people use sun-shading glasses to block the sun to reduce fatigue caused by eye adjustment or damage caused by strong light stimulation.
Light-colored sunglasses are not as good as sun-shielding mirrors, but they are rich in colors, suitable for use with various clothing, and have a strong decorative effect. Light-colored sunglasses are favored by young people because of their rich colors and diverse styles, and fashionable women love them even more. Special-purpose sunglasses have a strong function of blocking sunlight, and are often used in the field with strong sunlight such as beaches, skiing, mountain climbing, golf, etc., and their anti-ultraviolet performance and other indicators have higher requirements.
Different groups of people choose sunglasses according to different preferences and different uses, but the most fundamental thing is to start from the basic principles that can ensure the safety of the wearer and the vision is not damaged. Reducing strong light stimulation, clear vision without distortion, anti-ultraviolet, color recognition without distortion, and accurate identification of traffic signals should be the basic functions of sunglasses. If the above-mentioned functions are defective, the effect of sunglasses will be lost. In severe cases, symptoms of dizziness and swelling of the eyes will be caused. Sometimes symptoms of unresponsiveness, illusion of color discrimination, unequal walking, and traffic accidents will occur. . Therefore, when choosing sunglasses, you can’t just focus on style and ignore its inherent quality.
Lens classification
The types of sunglasses lenses are roughly divided into five types: anti-reflective protective lenses, colored lenses, painted lenses, polarized lenses and color-changing lenses.
1. Anti-reflective protective lens: This kind of lens is coated with a thin layer of magnesium fluoride on the surface to prevent the reflection of strong light, allowing you to see things more clearly and not interfered by strong light. To check whether your sunglasses really use anti-reflective protective lenses, you can point the glasses at the light source. If you see purple or green reflections, it means that the lenses are indeed coated with anti-reflective protective film.
2. Colored lenses: also called “dyed lenses”, it means adding some chemical substances in the lens making process to make the lenses show colors to absorb light of specific wavelengths. This is the most commonly used lens type for sunglasses.
3. Painted lens: The effect of this kind of lens is the same as that of colored lens, only the way of making it is different. It is to paint the color on the surface of the lens. The most well-known is “gradient colored lens”, the color is The top is the deepest, then it gets lighter down. Generally, sunglasses with power are mostly painted with lenses.
4. Polarized lenses: In order to filter the dazzling rays of the sun shining on the water, land or snow in equal directions, a special vertical coating is added to the lenses, which is called polarized lenses. It is most suitable for outdoor sports (such as marine activities, skiing or fishing).
5. Color-changing lens: It is also called “photosensitive lens”. Because the silver halide chemical is added to the lens, the originally transparent and colorless lens will turn into a colored lens when exposed to strong light for protection, so it is suitable for indoor and outdoor use.
6. Sunglass clip: Sunglass clip is a polarized sunglasses specially designed for nearsighted people, which effectively prevents glare and ultraviolet rays. It is especially suitable for outdoor sports such as driving, outdoor and fishing. Using polarized lens technology, the visual resolution is greatly improved. Eliminate 99% of reflected light and scattered light, making your vision clearer and smoother. The lens is specially reinforced with a film, which is effective in anti-wear, scratch and impact resistance.
7. Night driving lens: The night driving lens should be able to block more than 80% of the strong light of the opponent’s car, and the light transmittance of the main lens must be >75%. Observe the road without being affected. Wear a good driving night vision goggles at night. Not only can you clearly see the road surface, but also can effectively reduce the glare and glare and other harmful light from the headlights of the other party’s car. While blocking the strong light, you can see the road clearly, thus ensuring your driving safety.
Type characteristics
⑴Gray lens: The gray lens can absorb any color spectrum evenly, so the scene will only become darker, but there will be no obvious chromatic aberration, showing a real and natural feeling. Belongs to neutral colors.
⑵Brown lenses: filter out a large amount of blue light, which can improve visual contrast and clarity. It is better to wear under severe air pollution or fog. Generally, it can block the reflected light from a smooth and bright surface, and the wearer can still see the subtle parts. It is an ideal choice for drivers.
⑶Green lens: while absorbing light, it maximizes the green light reaching the eyes, so it has a cool and comfortable feeling, suitable for people who are prone to eye fatigue.
⑷Blue and gray lenses: similar to gray lenses, they belong to neutral lenses, but the color is deeper and the visible light absorption rate is higher.
⑸Mercury lens: The lens surface adopts high-density mirror coating. Such lenses absorb more reflected visible light and are suitable for outdoor sports people.
⑹Yellow lens: Strictly speaking, this type of lens is not a sunglass lens, because it hardly reduces visible light, but in foggy and twilight hours, yellow lens can improve the contrast and provide more accurate vision, so it is also called night vision mirror. Some young people wear “sunglasses” with yellow lenses as decoration.
⑺ Light blue, light pink and other lenses: the same lenses are more decorative than practical.
⑻Dark green lens: It absorbs heat and brings a cool feeling, but the light transmittance and clarity are low. It is suitable for wearing in the sun and not suitable for driving.
⑼Blue lens: Sun blue lens can be worn when playing on the beach and beach. Blue can effectively filter out the light blue reflected by the sea and sky. We should avoid using blue lenses when driving, because it will make us unable to distinguish the color of traffic signals.
