Four Things To Consider Before Knowing About The Sunglasses

1. What are sunglasses

Sunglasses, also called sun-shading mirrors, are used for sun-shading. People usually adjust the luminous flux by adjusting the pupil size 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 activities, especially in summer, it is necessary to use sunshade mirrors to block the sun to reduce the fatigue caused by eye adjustment or the damage caused by strong light stimulation.

So sunglasses should have become an indispensable thing in our lives. We can wear sunglasses in the hot summer, we can wear sunglasses when driving, and we can wear sunglasses when taking pictures of ourselves. It’s cool, and sunglasses are easy to carry. Women can put the glasses in their canvas tote bags and shopping bags. If you are a man, you can put them in the pocket of your suit. You can also put it in your car while driving, etc. Anyway, sunglasses are very convenient to use

So sunglasses should have become an indispensable thing in our lives. You can wear sunglasses in the hot summer, you can wear sunglasses when driving, and you can also wear sunglasses when taking selfies. Cool, sunglasses are easy to carry. Ladies can put their glasses in canvas tote bags and shopping bags. If you are a man, you can put them in the pocket of a suit. You can also put it in the car while driving. Sunglasses are very convenient to use anyway. Our factory’s sunglasses and optical frames have undergone strict quality inspections, and we are basically mechanized production now, just like in the wastewater treatment process we use the Water Treatment System With Pump, we use a semi-automatic USB soldering machine for the data cable of electronic products. We use a sewing machine to make canvas tote bags. We use a computer wire stripping machine to process cables. For the processing of the corners and corners of the frame, we use an automatic soldering machine to connect the various parts of the frame. , Enables us to improve production efficiency, reduce costs, and can give you a lower price.

2. The principle of sunglasses

Sunglasses effect

(Sunglasses)

(Sunglasses)

Sunglasses can block uncomfortable glare, and at the same time can protect the eyes from ultraviolet rays. All this is due to the metal powder filter, which can “select” the light when it hits it. Colored glasses can selectively absorb some of the wavelengths that make up the sun’s rays because they use very fine metal powders (iron, copper, nickel, etc.). In fact, when light hits the lens, the light is reduced based on the so-called “destructive interference” process. That is to say, when certain wavelengths of light (herein referred to as ultraviolet a, ultraviolet b, and sometimes infrared) pass through the lens, they will cancel each other out on the inside of the lens that is toward the eye. The overlapping of light waves is not accidental: the peaks of one wave and the troughs of the adjacent waves combine to cancel each other. The phenomenon of destructive interference depends on the refractive index of the lens (that is, the degree of deviation when light passes through different substances in the air), and it also depends 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. And the sunglasses should not be in direct contact with the sun.

Polarized glasses

Polarized glasses wearing effect

(Polarized glasses)

Polarized glasses provide another mechanism to protect the eyes. The reflected light from the asphalt road is relatively special polarized light. The difference between this reflected light and the light directly from the sun or any artificial light source lies in the problem of order. Polarized light is formed by waves that vibrate in one direction, while ordinary light is formed by waves that vibrate non-directionally. It is like a group of people walking in disorder and a group of soldiers marching in order. , Formed a sharp contrast. Generally speaking, reflected light is an orderly light. Polarizing lenses are particularly effective in blocking this light because of its filtering properties. This kind of lens only allows polarized waves that vibrate in a certain direction to pass, just like “combing” light. For road reflection problems, the use of polarized glasses can reduce light transmission, because it does not let light waves that vibrate parallel to the road pass. In fact, the long molecules of the filter layer are oriented in the horizontal direction and can absorb horizontally polarized light. In this way, most of the reflected light is eliminated, and the entire illuminance of the surrounding environment is not reduced, and the polarizer can face the sun directly.

Color changing glasses

(Color changing glasses)

(Color changing glasses)

(Color changing glasses)

(Color changing glasses)

 

(Color changing glasses)

 

(Color changing glasses)

The lenses of color-changing glasses can darken after the sun’s rays come in. When the lighting diminished, it became bright again. This is possible because the silver halide crystals are working. Under normal circumstances, it can keep the lens perfect transparency. Under the sunlight, the silver in the crystal separates, and the free silver forms small aggregates inside the lens. These small silver aggregates are irregular blocks with canine teeth. They cannot transmit light, but can only absorb light. As a result, the lens darkens. When the light is dark, the crystal re-forms, and the lens returns to its bright state.

3. Basic functions of sunglasses

Introduction

A pair of sunglasses looks very simple, that is, there are two colored glass or plastic sheets in a certain plastic or metal frame. Is there anything simpler than this? In fact, two glass lenses can make a lot of differences. When you use sunglasses, these differences will also have a great impact on you.

Functions

(UV damages the retina)

Ultraviolet rays can damage the cornea and retina, and high-quality sunglasses can completely eliminate ultraviolet rays.

When the eye receives too much light, it will naturally shrink the iris. Once the iris shrinks to its limit, people then need to squint. If there is still too much light, such as sunlight reflected from snow, it will damage the retina. High-quality sunglasses can filter out up to 97% of the light that enters the eye to avoid damage.

Certain surfaces, such as water, can reflect a lot of light, and the bright spots produced in this way can disturb the line of sight or hide objects. High-quality sunglasses can use polarization technology to completely eliminate such glare. We will introduce polarization technology later.

Certain frequencies of light will blur the line of sight, while other frequencies of light can enhance contrast. Choose the right color for the sunglasses, so that it can get better results in a specific environment.

If sunglasses do not provide UV protection, they will expose you to more UV rays. Cheap sunglasses filter out some of the light, causing your iris to open up to receive more light. This will also allow more ultraviolet rays to enter, increasing the damage caused by ultraviolet rays to the retina.

Therefore, there is indeed a difference between various sunglasses. For a specific use environment, choosing suitable and high-quality sunglasses will provide you with the greatest protection.

According to international standards, sunglasses are classified as personal eye protection products. The main function of sunglasses is to block the glare of the sun. However, international standards subdivide sunglasses into “fashion mirrors” and “general purpose mirrors.” The quality requirements of the “fashion mirror” in the standard are relatively low. Because the “fashion mirror” mainly focuses on style, the wearer pays attention to decoration rather than protection. In the standard, the quality requirements for “general purpose mirrors are relatively strict, including requirements for UV protection, diopter and prism.

4. Classification of sunglasses

Classification by usage

Sunglasses can generally be divided into three categories: sun-shading glasses, light-colored sunglasses and special-purpose sunglasses

(sun-shading glasses)

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 eye, it will cause damage to the human eye. Therefore, in outdoor activities, especially in summer, many people use sun-shading glasses to block the sun to reduce the fatigue caused by eye adjustment or the damage caused by strong light stimulation.

(light-colored sunglasses)

(special-purpose sunglasses)

(anti-reflective protective 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, so that you can see things more clearly and not be 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.

(colored lenses)

<2> Colored lenses: also called “dyed lenses”, it means adding some chemical substances in the manufacturing process of the lenses to make the lenses show colors to absorb light of specific wavelength. This is the most commonly used lens type for sunglasses.

(Painted lenses)

<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, and then it gets lighter down. Generally, sunglasses with prescriptions are mostly painted with lenses.

(polarized lenses)

<4> Polarized lenses: In order to filter the dazzling rays of the sun shining on 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).

(color-changing lenses)

(Sunglasses clip)

(Night driving lens)

Type characteristics

<1> Gray 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. It belongs to the neutral color system.

<2> Brown lenses: filter out a lot of blue light, which can improve visual contrast and clarity. It is better to wear under severe air pollution or foggy conditions. 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.

<3> Green 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.

<4> Blue 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.

<5> Mercury lens: The lens surface adopts high-density mirror coating. Such lenses absorb more reflected visible light and are suitable for outdoor sports people.

<6> Yellow lens: Strictly speaking, this kind 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.

<7> Light blue, light pink and other lenses: the same lenses are more decorative than practical.

<8> Dark 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.

<9> Blue lens: Sun blue lens can be worn when playing on the beach. The blue lens can effectively filter out the light blue reflected by the sea and the sky. We should avoid using blue lenses when driving, because it will make us unable to distinguish the color of the traffic signal.