What do polarized sunglasses mean?

2. Polarized sunglasses

What's the difference between polarized sunglasses and ordinary sunglasses?

What is polarization? Polarized light is also called polarized light. Polarized sunglasses use polarized lenses, which only allow light in a specific direction to pass through, thus filtering out more dazzling stray light such as diffused light and seeing more clearly. Visible light is a shear wave, and its vibration direction is perpendicular to the propagation direction. The vibration direction of natural light is arbitrary in the plane perpendicular to the propagation direction; For polarized light, its vibration direction is limited to a specific direction at a certain moment.

Can polarized sunglasses change color when seeing things? Color change is normal. It will check whether the glass installation is balanced, but it doesn't matter whether there is a screen or not. Good polarized sunglasses can look directly at the sun at night.

Polarization can be divided into three types, namely linear polarization, elliptical polarization and circular polarization, but generally it refers to linear polarization, also known as plane polarization. According to the use, it can be divided into ski goggles, fishing goggles, polarized driving goggles, outdoor sports goggles and golf glasses. Polarized sunglasses have many functions. Sunlight can be divided into visible light, infrared light and ultraviolet light. Ultraviolet rays can do harm to people's skin and eyes. Among them, ultraviolet rays can be divided into UVA, UVB and UVC (above 365,438+00 nm), and blue light UVA, UVB and UVC. These are harmful rays, and we should stop them, otherwise it will hurt our health. UVB will have a serious impact on vision, tanning rays will burn the skin, and polarized sunglasses can polarize the light, so it can block all harmful light without affecting the transmission of visible light, and really protect the eyes. There are other similar anti-glare, anti-road reflection, waterproof and so on. Polarized sunglasses are suitable for outdoor activities such as departure, fishing, travel and daily wear.

Ordinary sunglasses only use dimming function, because ordinary lenses can't filter light, so they can only reduce the intensity of glare and ultraviolet rays, but can't completely block these harmful rays. The function of ordinary sunglasses is only to reduce the damage to the eyes, but it also has the advantage of better mobility. Polarized sunglasses have polarized properties, which can completely block harmful rays such as scattering, bending, reflection, etc., and at the same time completely block ultraviolet rays harmful to glasses, so that people's eyes are not tired under strong light, achieving real protection and making what they see clearer and more stereoscopic.

To sum up, I suggest you choose polarized sunglasses, because for the sake of health, the advantages of polarized sunglasses are still relatively large. Of course, I don't reject ordinary sunglasses. Friends who like high popularity can choose ~ our goal is to choose the best, not the most expensive.

Polarized sunglasses-How to choose polarized sunglasses? take for example

Go out to play, the summer sun makes people hard to open their eyes. Besides umbrellas and hats, sunglasses are the best weapon against ultraviolet rays.

Dazzling light will penetrate your eyes and cause harm. Sunglasses can reduce the damage of strong sunlight to the eyes, and dazzling light can cause headaches. Sunglasses will have a filtering effect of 95~ 100. Most people still consider beauty when choosing sunglasses. They think that sunglasses are modern corrosive products, and the first consideration when buying them is the appearance of glasses. Even clothing stores will put a lot of sunglasses for people to choose and match their clothes.

Although sunglasses are decorative, their protection is the most important. Because if you don't block ultraviolet rays properly, it will cause damage to your eyes for a long time.

Ultraviolet light should be absorbed by the lens. If it is not fully absorbed and enters the retina, macular degeneration will occur, while if it is not fully absorbed, it will enter the lens, causing lens opacity, which will lead to serious eye diseases such as cataracts. Therefore, if you wear a pair of bad glasses, it will not only have no protective effect, but also hurt your eyes, which is not worth it.

How to choose a suitable pair of sunglasses? Five common dyed lenses: pink lenses: This is a very common color. It can absorb 95? Ultraviolet light and some shorter wavelength visible light.

In fact, this effect is similar to that of ordinary uncolored lenses, which means that pink lenses will not have greater protection than ordinary lenses. But for some people, it is quite helpful psychologically, because it feels more comfortable to wear.

Gray lenses: can absorb infrared rays and 98? Ultraviolet rays. The biggest advantage of gray lens is that it will not change the original color of the scene because of the lens, and the most satisfactory thing is that it can effectively reduce the light intensity.

Green lenses: Green lenses can be said to be represented by "Ray-Ban series" lenses. Like gray lenses, it can effectively absorb infrared light and 99? Ultraviolet rays. But the green lens will distort the color of some scenes.

Moreover, its light blocking effect is slightly inferior to that of gray lenses. However, green is still an excellent protective lens. Brown lens: This kind of lens absorbs light similar to green lens, but absorbs more blue light than green lens.

The degree of color distortion caused by brown lenses is greater than that caused by gray and green lenses, so the satisfaction of ordinary people is also low. But it provides another color choice, and can slightly reduce the halo of blue light, making the image clearer.

Yellow lens: absorbable 100? Ultraviolet, and can make infrared and 83? Visible light penetrates the lens. The biggest feature of yellow lens is that it absorbs most of the blue light.

Because when the sun shines through the atmosphere, it is mainly blue light (which can explain why the sky is blue). Yellow lenses can make natural scenery clearer after absorbing blue light. Therefore, yellow lenses are often used as "filters" or used by hunters when hunting.

However, no one can prove that the shooter is better at shooting because he wears yellow glasses. Pay attention to buying sunglasses: the human body has an instinctive reaction to protect itself. When the eyes encounter strong light, the pupils will naturally become smaller, which will reduce the ultraviolet energy entering the eyes. Once you wear glasses without ultraviolet protection, your pupils will become bigger. In addition, glasses have no function of isolating ultraviolet rays. At this time, the eyes are equal to the door wide open, and the damage to the eyes can be imagined.

Sunglasses can block ultraviolet rays because the lens is coated with a special film, while inferior sunglasses can not only block ultraviolet rays, but also seriously reduce the transmittance of the lens, enlarge the pupil, and inject a large amount of ultraviolet rays, causing harm to the eyes. In addition, inferior lenses can also cause symptoms such as nausea, forgetfulness and insomnia.

The color of sunglasses is light gray, brown or light smoke, followed by green, amber and blue. Red is only used for sunbathing or snow. It is best to use polarized sunglasses in the car, because it can reduce glare.

If you wear sunglasses, others can see your eyes clearly, then your lenses are too light. When the sun goes down, we'd better take off our sunglasses, otherwise, our eyesight will be affected in the weak light.

You should go to a regular optical shop and choose sunglasses with anti-ultraviolet function produced by regular manufacturers. Pay attention to the lens surface when choosing.

People with slender faces are suitable for round-rimmed sunglasses. Medical experts suggest that when buying sunglasses, you can judge whether your eyesight is clear or not.

To buy high-quality sunglasses, the only thing you can do is to go to specialty store and regular optical shops to buy sunglasses. .

What is a polarizer? What does it do? How to use it specifically? Under what circumstances? An object or part made of a certain material

A polarizer is made according to the polarization principle of light. We know that when sunlight is projected on the road or water surface, it will directly dazzle the eyes, make people feel dizzy and tired, and can't see clearly for a long time. Especially when you are driving a car or doing outdoor entertainment, it will not only affect our work and entertainment mood, but even affect our judgment of objects and images, thus creating danger. Long-term direct sunlight can also lead to a rapid decline in vision, resulting in myopia, hyperopia, astigmatism or cataract. The special function of polarizer test is to effectively eliminate and filter the scattered light in the beam, so that the light enters the eye visual image on the right axis and the field of vision is clear and natural. Like venetian blinds, the light is adjusted to the same direction and enters the room. Naturally, the scenery looks soft and not dazzling. Polarizers mostly appear in the application of sunglasses, which is a necessary equipment for car owners and fishing enthusiasts. It can help drivers filter out the oncoming high beam and let fishing enthusiasts see the fish floating on the water. In the past, polarizers were only available in internationally renowned sunglasses, but at present, there are many domestic brands of regular polarizers. According to the mechanism of filtering polarized light, polarizers can be divided into two types: circular polarizer (CPL) and linear polarizer (LPL), which have the same function. LPL is mainly used for old-fashioned manual focus cameras. The CPL, which appeared late, has a thin film with the wavelength of 1/4, which has a special property and can produce π/2 phase shift for the polarized electric vector in one direction (assuming X). But it has no effect on the electric vector perpendicular to it (assuming y). Therefore, the above polarized light can pass through the 1/4 wave plate along the angular bisector of X and Y, so the emergent light is a beam of polarized light with vertical polarization direction and π/2 phase difference. The so-called circularly polarized light. This design makes it more suitable for new autofocus and automatic exposure cameras. At present, cameras using AF lens (interchangeable camera lens with autofocus function) all use CPL as polarizer. In some light conditions, the linear polarizer may mislead the built-in photometric elements to measure light, so DC and most autofocus cameras use circular polarizers. The function of PL mirror is to filter reflected light. Increase the imaging contrast. Its working principle is to selectively filter light from a certain direction. By filtering out a lot of polarized light in diffuse reflection, the light intensity in the sky is weakened, the sky is darkened, and the contrast between the blue sky and white clouds is increased. When shooting, look at the viewfinder and rotate the front mirror. The effect is most obvious when the sky is darkest in the viewfinder. The darkest light differs from the brightest light by 90 degrees. You can adjust it to any angle between the darkest and brightest as needed. PL mirror can also effectively weaken or eliminate the reflection from nonmetallic surface, which is typical polarized light (the light reflected from metal surface is not polarized light, so the polarizer has no influence on it). By adjusting the polarizer, this part of the reflection can be filtered out, thus improving the imaging quality of the subject and the clarity of the picture. For example, by using a polarizer, the reflection of the water surface can be weakened, so that the fish in the water can be photographed clearly. When shooting such a scene, the projection angle of the light source should be close to the shooting angle of the camera, and its maximum deflection angle should be between 30 and 40 degrees. When in use, it can be adjusted by slowly turning the lens in front of the filter to minimize the reflection on the scene surface. In addition, the polarizer can effectively improve the color saturation and contrast. This is because the polarizer can absorb the stray light reflected by fog or dust in the atmosphere in all directions, thus making the photographed image more pure. For example, in still photography of flowers and other things, polarizers are often used to take color photos. It is very useful in landscape photography, flower photography and shooting some specific scenes with strong reflection. When the polarizer is used to take landscape photos, it has an excellent effect on the description of clouds. The refractive index of light in the blue sky is greater than that of light scattered by white clouds. Polarizers can also make the color of green leaves more saturated and eliminate the fog of shooting urban scenery at low angles. The polarizer consists of a lens body and a rotatable rear seat frame connected with it. The lens body includes a grating made of very fine crystal glass. When rotating, the grating of the polarizer blocks polarized light rays that are not parallel to it. Therefore, the polarizer can control and selectively record the amount of reflected light parallel to it (this reflected light is polarized light). This is the reason why the polarizer can eliminate or weaken the reflection from the nonmetallic surface. However, most polarizers are a little blue, and when used for shooting, they will block some unpolarized light in the same direction as polarized light. In order to avoid the color of the picture being too dim, it is generally necessary to increase more than one exposure. Although the polarized lens with the characteristics of this paragraph can filter out a lot of irregular light interference and avoid glare and glare, if the curvature of the lens itself cannot be in the refractive state of optical standards, the polarization effect will be weakened, which will affect the authenticity of the image and have poor durability. Ordinary polarized sunglasses on the market are made of fiber-sandwiched polarizing films. It is different from optical glass polarized sunglasses because of its soft texture. The arc bending is unstable. After the lens is assembled on the frame, it is difficult for the lens to reach the optical refractive standard, and the visual image is loose and deformed. Because of the instability of arc bending, the lens is deformed, which directly leads to poor clarity and distortion of transparent images, and can not achieve normal visual effects. The surface is easy to be scratched, worn and not durable. Notes for editing this paragraph 1. There are linear polarizers (linear polarizers) and circular polarizers. Circular polarization can make light pass through the filter in a circular direction instead of a straight line, which is especially suitable for cameras with autofocus system. When using a SLR mirror, because the mirror is used in the camera, the circular polarizer can ensure the focusing accuracy. Cheaper linear polarization may affect the autofocus of some cameras, so if digital cameras use polarizers, they should use circular polarization. It is best not to use it with other filters, otherwise it will easily form black corners in the picture. 3. The polarizer itself will absorb about 75% of the light. If it is used on cloudy days, or when taking snapshots with a small aperture, it is best to stabilize the fuselage with a tripod. Because digital cameras use TTL to measure light, there is no need to measure light.

Polarized sunglasses What are polarized sunglasses?

The polarizer is good, and its special function is to effectively eliminate and filter the scattered light in the beam.

So that light can be injected into the human visual image on the light transmission axis on the correct track, and the visual field is clear and natural. Like venetian blinds's principle, adjusting the light to the same direction and entering the room naturally makes the scenery look soft and not dazzling.

Polarizer appears in the application of sunglasses, which is a necessary equipment for car owners and fishing enthusiasts. It can help car owners filter out the oncoming high beam and let fishing enthusiasts see the fish floating on the water. In the past, polarizers were always available for internationally renowned sunglasses, and polarizers were also widely used for domestic brand "BeiJing2008" Olympic licensed sunglasses authorized by the Olympic Organizing Committee.

In the scorching sun, or playing on the lake with big waves, or driving in a glass building or on a flat road, at that time, the eyes were uncomfortable and dizzy, which were all caused by strong light reflection. This kind of strong light reflection brings great inconvenience to our life, travel and driving in special summer, and even has certain security risks.

At this time, we need to wear a pair of sunglasses, but ordinary sunglasses can only block strong light and ultraviolet rays, but there is nothing we can do about the reflected light and scattered light that make us dizzy. Now with polarized sunglasses, the trouble caused by strong light is completely solved.

I suggest you go to McDaniel Mall.

What's the difference between polarized sunglasses and ordinary sunglasses?

What is polarization? Polarized light is also called polarized light. Polarized sunglasses use polarized lenses, which only allow light in a specific direction to pass through, thus filtering out more dazzling stray light such as diffused light and seeing more clearly. Visible light is a shear wave, and its vibration direction is perpendicular to the propagation direction. The vibration direction of natural light is arbitrary in the plane perpendicular to the propagation direction; For polarized light, its vibration direction is limited to a specific direction at a certain moment.

Can polarized sunglasses change color when seeing things? Color change is normal. It will check whether the glass installation is balanced, but it doesn't matter whether there is a screen or not. Good polarized sunglasses can look directly at the sun at night.

Polarization can be divided into three types, namely linear polarization, elliptical polarization and circular polarization, but generally it refers to linear polarization, also known as plane polarization. According to the use, it can be divided into ski goggles, fishing goggles, polarized driving goggles, outdoor sports goggles and golf glasses. Polarized sunglasses have many functions. Sunlight can be divided into visible light, infrared light and ultraviolet light. Ultraviolet rays can do harm to people's skin and eyes. Among them, ultraviolet rays can be divided into UVA, UVB and UVC (above 365,438+00 nm), and blue light UVA, UVB and UVC. These are harmful rays, and we should stop them, otherwise it will hurt our health. UVB will have a serious impact on vision, tanning rays will burn the skin, and polarized sunglasses can polarize the light, so it can block all harmful light without affecting the transmission of visible light, and really protect the eyes. There are other similar anti-glare, anti-road reflection, waterproof and so on. Polarized sunglasses are suitable for outdoor activities such as departure, fishing, travel and daily wear.

Ordinary sunglasses only use dimming function, because ordinary lenses can't filter light, so they can only reduce the intensity of glare and ultraviolet rays, but can't completely block these harmful rays. The function of ordinary sunglasses is only to reduce the damage to the eyes, but it also has the advantage of better mobility. Polarized sunglasses have polarized properties, which can completely block harmful rays such as scattering, bending, reflection, etc., and at the same time completely block ultraviolet rays harmful to glasses, so that people's eyes are not tired under strong light, achieving real protection and making what they see clearer and more stereoscopic.

To sum up, I suggest you choose polarized sunglasses, because for the sake of health, the advantages of polarized sunglasses are still relatively large. Of course, I don't reject ordinary sunglasses. Friends who like high popularity can choose ~ our goal is to choose the best, not the most expensive.

What's the difference between polarized sunglasses and ordinary sunglasses?

Polarizing lens, also referred to as PL lens, is composed of two optical lenses with a tiny polarizing crystal with directional function. This tiny polarizing crystal can produce a very fine fence-like structure, allowing only light with the same vibration direction and gap to pass through. This selectively filters light from a specific direction. By filtering out many polarized light in diffuse reflection light, the intensity of external light is weakened, the sky is darkened and the contrast of blue sky and white clouds is increased. So as to improve the quality and clarity of the seen object. In addition, the polarizer can effectively improve the color saturation and visual contrast, thus making the color of the scene more pure.

The difference between polarizer and sunglasses;

Sunglasses are common colored glasses that we are familiar with to keep out the sun. Ordinary sunglasses can only reduce the light intensity, but can't effectively remove the bright reflection and glare in all directions. In our daily life, in addition to sunlight and ultraviolet rays, light will produce irregular diffuse reflection when it passes through roads, water surfaces and other places in disorder, commonly known as "glare". The appearance of glare will make people feel uncomfortable and tired, affect the clarity of things, and bring a lot of trouble to people's life and travel, especially to drivers.

Because of its high cross filter layer, polarizer can effectively filter out all kinds of glare and ultraviolet rays up to 100%, which can not only reduce the light intensity, block glare, improve visual contrast and improve visual clarity. Previously, due to the manufacturing process, polarizers were only used as lenses for high-end cameras and camcorders, and there were few polarizers for sunglasses.

How to distinguish between ordinary sunglasses and polarized lenses;

There are many ways to distinguish polarizers, one of which is simple: if two polarizers are vertically stacked, the lens will be opaque. The reason is that the special design of polarizing lens only allows parallel light to pass through the lens, and most of the light is blocked when the two lenses are stacked vertically. When you buy, you can immediately know the authenticity and quality of the product by such a simple operation.

Specific experience, in the sun, polarizers are much more comfortable than sunglasses, and of course the price is much more expensive than ordinary sunglasses. Ordinary polarizers are about 200, and thousands of professional outdoor polarizers are normal.

What's good about polarized sunglasses?

The harm of ultraviolet rays to human body is cumulative, that is to say, the longer exposure to the sun, the greater the harm of ultraviolet rays.

A statistical report in the United States shows that 80% of the ultraviolet rays a person is exposed to in his life are accumulated by exposure to the sun before he is eighteen, so to avoid the harm of ultraviolet rays, he must start from childhood. Parents should teach their children the correct concept, form the habit of wearing sunglasses from an early age, and reduce the accumulation of ultraviolet rays to the eyes.

When choosing sunglasses, don't think that the darker the lens, the stronger the anti-ultraviolet effect. Conversely, the darker the color, the larger the pupil will become. If it is not a safe anti-ultraviolet lens, the more ultraviolet rays the eyes are exposed to, the more serious the damage will be.

Therefore, it is best to confirm that the lens can effectively block more than 99% of ultraviolet rays (including ultraviolet rays A and B), and at the same time, it should have polarization characteristics to eliminate glare (glare means that strong light reflected from some angles will temporarily make people unable to see clearly). Polarized glasses have more polarization angle theory. In order to meet these strict optical requirements, responsible manufacturers often have to invest huge amounts of money, personnel and equipment to design and manufacture it.

The quality of sunglasses on the market is very different, and the price is also very different, which is why! To avoid the damage of ultraviolet rays to eyes, of course, we should try our best to reduce exposure to strong sunlight, especially between 10 in the morning and 2 pm, which is when the sun shines directly on the earth's surface and the intensity of ultraviolet rays is the highest. Especially those ultraviolet rays reflected by concrete, snow, beach or water surface are the most powerful and harmful to the eyes, but they are also the most easily overlooked.

So, if you want to be active in these places for a long time, remember to wear appropriate polarized sunglasses. Principle of polarized sunglasses: Natural light (unpolarized aurora) is actually composed of electromagnetic waves vibrating in a specific direction, and reflected or scattered light usually prefers a specific direction, which is why polarized sunglasses can filter out sunlight reflected from roofs or pools; After the natural light is filtered by the polarizer, it can only let the light in one direction pass, that is to say, the polarizer can polarize the light first, and then only let the light in one direction pass (visible light) (as shown in figure 1).

Polarized sunglasses use this feature to block harmful light (as shown in Figure 2), because sunlight will produce harmful glare due to natural reflection or refraction when it touches any object, and polarized sunglasses can completely absorb these strong lights that will cause glare and eye damage ◆ Comparison between ordinary sunglasses and polarized sunglasses: Ordinary sunglasses only use dimming function, because ordinary lenses cannot filter light. Therefore, the intensity of strong light, ultraviolet rays and the like can only be reduced. , can't completely block these harmful rays (as shown in figure 3-A), so its role is only to reduce the damage to the eyes, but the biggest advantage of ordinary sunglasses is their popularity. Polarizing lens has polarization characteristics, so it can completely block dazzling glare caused by scattering, refraction, reflection and other factors.

At the same time, it can completely block ultraviolet rays harmful to human eyes (as shown in Figure 3-B), so that people's eyes will not be tired after long-term activities under strong light, achieving the real protection effect and making what they see clearer and more stereoscopic (as shown in Figure 4). ◆ The role of polarized sunglasses: In life, too many light sources will produce harmful light, especially sunlight; There are three kinds of light emitted by sunlight: visible light, infrared light and ultraviolet light (as shown in Figure 5).

Among them, ultraviolet rays cause serious harm to human skin and eyes. Among the rays released by sunlight, IR (Infra-red) infrared ray (750mm) and visible light layer (310 ~ 780 nm); Ultraviolet rays can be divided into UVA, UVB and UVC (above 310 nm). In blue light, UVA, UVB and UVC are all harmful rays. If exposed for a long time, UVB will cause serious harm to the body, and tanning rays will burn the skin. Most eyes will absorb this UVB radiation, so this light source must be blocked. Polarized sunglasses have the function of polarized light, which can block all harmful rays without affecting the transmission of visible light, and can really protect the eyes.

◆ Application of polarized sunglasses: Polarized sunglasses can block 100% harmful light, so it can be applied to: 1. Medical treatment: patients undergoing eye surgery need all-round protection, and polarized sunglasses are the best choice. 2. Outdoor activities: such as skiing, fishing and water sports. Everyone needs sunglasses that can completely block harmful light to avoid eye injury or fatigue.

3. Goggles ◆ Types of polarized sunglasses: So how do you choose polarized sunglasses? Polarized sunglasses with different colors have different characteristics. Pink or vermilion lenses can deepen the contrast and sharpness under strong light, which is very suitable for water activities and snow activities.

Brown or brown lenses are the first choice for drivers because they can enhance the contrast of colors. Amber, yellow or orange lenses are very suitable for wearing on cloudy days and can have a very clear field of vision, but they are not suitable for use in the big sun.

Gray or dark green lenses can keep the most natural primary colors when watching things, which is a good choice. Sunglasses are not only needed in summer, but also all year round.

Wear it on sunny and cloudy days. Don't think that if the sun is not strong and the weather is not hot on cloudy days, you will take it lightly and unconsciously expose more harmful ultraviolet rays.

Therefore, even on cloudy days with thin clouds, we must refer to the forecast of ultraviolet index and prepare for sun protection.