How to choose sunglasses? Polarized sunglasses

Choosing sunglasses, the main thing is to pay attention not to the cost and design, but to the degree of protection from ultraviolet rays, and of course to the license. Eye health is the dominant factor, image and fashion - then.

How to choose the right sunglasses

Ignore glasses with small narrow lenses. With them, the meaning of protection is generally lost, because. narrow lenses will allow ultraviolet rays to pass around them, although the field of view will be limited. This factor will only increase the load on the eyes, because the natural reaction of the eye when the field of vision is darkened is the expansion of the pupil. Nerve receptors that respond to the degree of darkening are located in the center of the retina. As a result, the eye, deceived by the decrease in illumination created only in the center of the field of view, opens the pupil and the ultraviolet flow begins to burn the retina itself without hindrance.

If glasses with lenses of a normal size, but of low quality, then the same thing happens. Dark lenses cause the pupil to expand - the eye does not know that these low-quality lenses darken only the visible spectrum, and all the harmful ultraviolet is passed onto the defenseless retina of the eye and also burns it out.

What is most unfortunate is that outwardly a fake from a quality product can only be distinguished by a specialist, and even then with the help of specialized equipment. And the result of wearing a fake will not appear immediately, and the consequences may be irreversible, up to complete blindness. This is just the example when it is forbidden to save, because. in this case, the stingy (or deceived) pays not twice, but for the rest of his life. Moreover, in most cases, he will not even understand (or not believe) what caused the deterioration of vision.

If, after spending the day in new sunglasses, watery eyes appear, or you notice pain in the eyes in bright light, or even blurred vision, then most likely the eyes were damaged by the attack of ultraviolet radiation. The most reasonable way out in this situation is to immediately run to the ophthalmologist.

Prolonged exposure to UV radiation can cause sunburn of the cornea, called photokeratitis, which can lead to temporary loss of vision. This phenomenon is observed in skiers or polar explorers, therefore in ophthalmology it is called "snow blindness". Also, photokeratitis is not uncommon among vacationers in equatorial resorts.

Remember:

• The closer you are to the equator or the higher in the mountains, the more aggressive the avalanche of UV rays hits your eyes.
• And one more rule - the closer to large water surfaces, the more powerful the reflected flux of UV radiation. So the more you need quality sunglasses.

So if you yourself do not know how to choose the right sunglasses, then there are two options:

1. Buy only certified goods from a recognized manufacturer, and only from a seller who guarantees the quality of the product. (at the end of the article I will give some links to the sunglasses store)
2. Do not buy sunglasses at all - the natural protective reaction of the eye itself will adjust the degree of aperture opening and automatically set the flow of transmitted light to the optimal safe level.

Now let's talk about quality criteria.

Glass or plastic

If the manufacturer maintains the standards, then they protect both those and those qualitatively. So do not bother with the choice between glass and plastic.

There is an opinion that high-quality glasses can only be equipped with glass lenses. This is a myth, even such a recognized cult company as Ray Ban, in addition to traditional glass, has long been releasing models from high-tech organic plastic.

The only difference is the price of such plastic. If cheap options are made of acrylic that transmits UV rays, then expensive ones are made of polycarbonate. This polymer reliably protects the eyes from ultraviolet radiation, does not scratch and is safe for health.

If you are firmly convinced that the material of your sunglasses should certainly be glass, but doubt the words of the seller, then you can check the composition in the only easy way. Just put the lens on your cheek or lips - glass, unlike polymer, will be cold, even in hot weather.

Pros and cons of plastic lenses

• Plastic is safer to use. It is advisable for children to take glasses made of plastic.
• It is easier to apply protective coatings on plastic.
• Plastic is lighter.
• Easily scratched. If scratches or cracks form, stop using the glasses immediately, as this can cause vision problems.
• Possible optical distortion.
• Deformed at high temperatures.

Pros and cons of glass lenses

• Glass lenses initially do not transmit ultraviolet light. Provides acceptable UV protection even without the use of protective coatings.
• Less optical distortion than plastic.
• Glass lenses are scratch resistant.
• The main disadvantage is fragility. Glass sunglasses are not recommended for children and athletes.
• Glass is heavier than plastic.

Quality plastic is a good alternative. During the production process, special additives are introduced into the composition, and protective layers are applied during the manufacture of lenses. An unpleasant nuance may be the distortion of objects, but this factor must be assessed directly by trying on glasses: straight lines should not change shape.

Sunglasses color

The phrase "sees everything in pink" has nothing to do with glasses. To cheer up, it is not enough to have pink glasses, on the contrary, if this shade is close to red, it can adversely affect the psyche.

The color of the lenses of sunglasses affects the natural color rendering of the surrounding world and the choice depends only on personal preferences. Although, of course, it is useful to know how certain shades affect the reaction from the perception of the filtered surrounding world.

Shades of brown, dark gray and dark green are recognized as the most optimal: in the first two, the color rendition corresponds to reality as much as possible, in the third, harmful rays are filtered to the maximum and the eyes are less tired.

Yellow and orange filters block blue color, help with worsened weather conditions when the sun is not bright. In conditions of significantly reduced illumination, these filters shift the reaction of the photoreceiving system of the eye towards amplification and the surrounding space becomes brighter, especially at night. There are even goggles for night driving based on this effect, they just add a layer that dampens the direct light from the headlights.

• Gray and brown are the best colors for vision. Maximum natural color rendering.
• Green - maximum filtering of harmful ray ranges.
• Pink - helps reduce eye fatigue.
• Yellow and orange are of little use, unnecessarily overload the retina and have a negative effect on the central nervous system.
• Red - impairs coordination of movements, up to loss of orientation in the area.

Additional properties

Here are a few important features to consider when choosing the right sunglasses. Manufacturers add various effects to products: mirror reflection, uneven darkening, polarization, photochromism. And this is not for style, but for functionality. There is a scientific explanation for everything.

A protective coating with a mirror effect is designed to eliminate various glare from surfaces such as snowy mountains, the sea or wet road surfaces.

Polarized lenses are also able to neutralize glare reflected from surfaces. At the same time, they do not distort the color balance at all, but only cut off the circular light wave, turning it into a flat one.

Gradient lenses, darkest at the top with a gradual fading downwards, are functional when protection is needed only from bright skies and direct sunlight. For example, specialized glasses for motorists, recommended for drivers at low sun positions. This option can lead to eye fatigue, so for everyday wear it is desirable to choose an even shade.

Photochromic lenses smoothly adapt to changes in light intensity. This property is realized in chameleon glasses that darken in the sun, or become transparent when the brightness of the light decreases. They are coated with special substances - photochromic agents. Attention! At high temperatures, photochromic agents are less active than at low temperatures. That is, in the heat, the rate of darkening of photochromic lenses weakens, and the eyes may not receive protection in time. When choosing photochromic lenses, take into account, in addition to the speed of darkening and lightening, also temperature sensitivity. Over time, the light-chemical coating may "get tired", and the darkening will weaken. Therefore, chameleon glasses must be replaced regularly.

Lens marking

When choosing glasses, pay special attention to the "ultraviolet" marking, which shows the degree of protection against ultraviolet rays as a percentage.

The inscription "400 nm" refers to the maximum wavelength that sunglasses protect against. If the specified number is less than 400, then part of the rays will pass through the filter.

The manufacturer's label might look like this:

• UV-A - the highest degree of protection,
• UV-B - medium degree.

The first is designed for operation under conditions of strong solar insolation, for example, on the beach. The second is placed on glasses that can be used in everyday life.

In addition to this marking, not letters, but numbers may be indicated indicating the maximum wavelength of ultraviolet light that the glasses are able to filter.

Glasses tagged:

• UV 400 filters up to 99% of ultraviolet,
• UV 380 - 95% UV rays.

1. The first is acceptable in a cloudy sky, when the sun alternately hides behind the clouds.
2. The second is designed for urban conditions, when lighting conditions change during the day. These glasses can be worn indoors.
3. Lenses of the third category are the most common and versatile. Suitable for both beach holidays and for motorists.
4. The fourth degree of protection is designed for especially dangerous mountain conditions. Recommended for climbers and skiers. Sold exclusively in specialized sports or tourist stores. Driving a car is strictly prohibited.

Shading and UV protection levels fall into five categories:

• "0" - 80-100% light transmission. Minimum UV protection for all ranges.
• "1" - 43-80% light transmission.
• "2" - 18-43% light transmission.
• "3" - 8-18% light transmission. Recommended for ordinary trips to nature and beach holidays in non-equatorial latitudes.
• "4" - 3-8% light transmission. Very dark filter, designed for tropical countries and highlands.

frame

Tips like “how to choose the right frame, correct the shape of the face or choose a fashionable style” will not be considered in this article, I will only note the basic principles.

• Blondes (and blondes) are more suited to the face of gold, silver, pale blue and light green frame colors.
• Fair-haired will look more interesting with copper frames or gold.
• Brunettes and brown-haired women look best in shades of brown, gold, and red frames.

The frame of the glasses should fit snugly, especially to the upper part of the face, but without squeezing the temples and the bridge of the nose. Otherwise, it can provoke fatigue, up to a headache.

Sunglasses protect the skin around the eyes

This is a secondary property, but still - properly selected high-quality sunglasses can protect not only the eyes, but also the sensitive skin around them, which is important as a factor protecting against premature skin aging.

For most, the main recipe for youth is not a secret: if you don’t want to grow old, protect your skin from the sun’s rays. Statistics says that the main part of wrinkles appears precisely as a result of exposure to the sun on the skin. And the thin delicate skin near the eyes needs special protection, not to mention the eyes themselves.

Even super-expensive high-quality cosmetics with sun protection factors will not give such protection as high-quality glasses provide (tens of times higher than the sun-reflecting properties of advertised sunscreens).

Sunglass models and manufacturers

Ray Ban is considered to be the universally recognized world leaders, although other companies producing fashion accessories have impressive collections of sunglasses - Armani, Adidas, Dior, Dolce & Gabbana, Prada. Buying them in our time is not a problem, because proven brands are a guarantee of quality. Only it is necessary to take into account the dominance of fakes in the Russian market, and even more so in the Ukrainian one. It is more reliable to order genuine sunglasses in an online store, having personally verified their authenticity, and read customer reviews there.

Where to buy the best sunglasses

According to statistics, among the world's eyewear manufacturers, the most popular models are:

• aviator - Ray Ban (Aviator)
• Wayfarer - Ray Ban (Wayfarer).

Summarizing

• It is advisable to know in advance for what purposes sunglasses are required. If there are eye diseases or vision problems, consult an ophthalmologist first.
• For sports in snowy conditions, it is preferable to purchase sunglasses with polarized lenses.
• With a frequent sharp change in the brightness of the lighting (exiting the building into the sun), it is advisable to buy sun glasses with photochromic lenses.
• Read the label carefully to see what UV rays the glasses protect against and whether they can reduce glare or adapt to the brightness of the light.
• Do not buy sunglasses in the markets and street stalls. Of course, high-quality glasses do not have to be expensive, but health is more important than savings.

Just approach the choice without fanaticism. It has been personally verified that high-quality $10 sunglasses and $350 fashion branded sunglasses protect against UV rays equally. And all the games with pricing are just marketing perversions of sellers, how to sell the same thing at a higher price under the image of a trendy brand. Go through the catalogs of European stores and you will be surprised - there are sunglasses for 800 euros. And what is interesting - the buyers are also on them.

Indeed, the rich have their own quirks.

Or maybe not everything is so simple? Maybe the price of health is really worth such prices?

Hardly ... More like a phobia. If only they had our salaries...

Video

How to choose the right sunglasses

The selection of sunglasses is an important and difficult task. If you think that it is only about fashion brands, then you are greatly mistaken. Did you know that when you are going to walk around the city on a sunny day and packing your bags for a vacation at the sea, you should take different sunglasses?

Everyone knows that sunlight contains ultraviolet rays that are harmful to humans and must be protected from. Do you think that glasses save from them? Not at all. Ultraviolet rays such as UV-A and UV-B completely block ordinary transparent glass and some types of plastic. There is also a third type of UV rays "C", but the ozone layer of the earth's atmosphere successfully copes with it. By the way, since we are talking about ultraviolet, reflective surfaces greatly increase the harmful effect of UV rays. That is why it is easy to get burned in the mountains and at the sea (snow reflects light by 90%, the water surface by 70%), and it is difficult on the shore of a forest lake or river (the reflectivity of green grass is only 30%). All these radiations are not visible, but only perceptible. And the dark glasses of sunglasses are designed to save our eyes from the visible part of the harmful sunlight. It is the visible bright light that makes us squint our eyes and “make faces”, albeit not on purpose.

So, all sunglasses have a filter designed for different degrees of illumination. In total, there are 5 degrees of protection for our eyes, and on the product of a responsible manufacturer, the category of sunglasses filter is indicated by the corresponding number.

• "0" means that the lenses of the glasses transmit 80-100% of the light. This is the lowest degree of protection, such glasses are suitable only on a cloudy day.
• "1" - 43-80% light transmission. Ideal for days when dense clouds give way to clear skies, that is, for partly cloudy and only for the city.
• "2" let in 18-43% of the light and are also suitable for urban life. A bright sunny day, a shopping trip - these are the ideal conditions for putting on glasses marked "2".
• "3". Light transmittance - 8-18%. Sunglasses with filter categories "1" and "2" are suitable for everyday urban life, and only these, marked "3", can and should be chosen for a trip to the sea. Such protection will withstand both sunbathing on the beach and boat trips.
• "4" means the highest degree of protection of the retina from damaging light. Throughput 3–8%. The choice of such filters for glasses belongs to climbers and tourists climbing mountains.

As you can see, choosing glasses is not so easy. It is hardly worth expecting the necessary amount of important information about each item of goods on street stalls, where not every unit of goods has packaging. Once you've tried trusting a real quality sunscreen company, you're unlikely to want to go back to a suspect market range. Ours could be one of the best purchases of your life. The world famous brand RB has already made the lives of millions of people brighter and their views safer.

Take advantage of the best, because you are already with us!

When choosing regular sunglasses, the main criteria are attractive design, comfortable wearing and, of course, effective protection from sunlight. Another thing - sunglasses for outdoor activities and extreme sports. They should not only delay harmful ultraviolet radiation, but also protect the eyes from wind, dust, snow, rain, mechanical stress and changes in the intensity of the light flux. Modern high-tech sports glasses fully meet these requirements. Impact resistance is provided by materials such as polycarbonate and trivex, and high-definition vision is provided by high-quality polarized lenses that neutralize light reflection from the surface of ice, wet asphalt and water. Sports glasses are very diverse, so when buying them, you must take into account the features of a particular sport.

Today, most manufacturers produce glasses with a set of interchangeable lenses for different lighting conditions, which makes it possible to use them at any time of the day and in any weather. People with visual impairments can purchase spectacles with a special Optical Clip, where appropriate corrective lenses can be inserted. There are also glasses that provide for the installation of diopter lenses of the required darkening and color instead of the main lenses.

What is the importance of the color of the lenses and the degree of their darkening

Two main parameters of sunglasses depend on the color of the lenses and its intensity: light absorption and light transmission. The amount of light transmission indicates what percentage of sunlight passes through the lens, and is determined by the average value of the light transmission coefficient.

2 - light transmission is 18–43%.

3 - lenses transmit 8–18% of light.
4 - less than 8% light transmission (very dark lenses fall into this category).

Meaning of lens color for sports glasses

The color of the lenses of sports glasses is chosen depending on the sport and weather conditions.

Glasses with clear or slightly tinted lenses are suitable for protecting your eyes from dust, wind, sand, insects and of course UV radiation. These glasses are optimal for outdoor recreation in low sunlight or at dusk.

Amber and yellow lenses enhance the contrast of vision, so they are often recommended for hunters and cyclists. Mirrored lens coatings will reduce light reflection and help cyclists see the road better.

Green and blue lenses are suitable for tennis players: through them the ball is clearly visible against the background of the court or grass.

For water sports enthusiasts, it is better to wear glasses with polarized lenses. The main advantage of these lenses is the ability to neutralize the light reflected by the surface of the water.

Gray lenses retain natural lighting, do not distort color perception, and neutralize bright sunlight. They are necessary for fishermen to fish in shallow water.

Useful for fishing and goggles with lenses of yellow and brown. Yellow lenses are good in low light conditions: in fog or twilight, and brown lenses are good in bright light.

For fans of winter sports, goggles with
orange and brown lenses. Orange lenses allow you to see the topography of the snowy terrain better on cloudy weather, and brown lenses on a clear sunny day. It will not be superfluous and a mirror coating to reduce light reflection.

Iridescent mirrored lenses shimmer in different shades of gray and blue. They soften the irritating effect of bright sunlight and increase the contrast of vision. Glasses with such lenses are optimal for recreation and sports in the mountains and on the water.

Specialized sunglasses are a mandatory attribute of cyclists, climbers, skiers, hunters and fishermen, shooters, tennis players, yachtsmen and people leading an active lifestyle. Modern technologies provide maximum comfort and safety of using glasses when practicing various sports.

For the right choice, you need to understand that sunglasses have become one of the most important style-forming accessories; Almost no major fashion show can do without them. As a result, many consumers today perceive sunglasses primarily as a kind of style element, often completely unjustifiably forgetting about their main purpose.

Tip 2. When planning to purchase new glasses, decide where and when you are going to wear them. If you need glasses for sports - this is one story (see section), if you are preparing to spend the summer months at sea or in the mountains - another, but if you intend to use sunglasses mainly in the city - the third. Well, if you spend a lot of time driving and would like to make driving more comfortable with the help of glasses, then this is a separate, fourth story (see). Having decided on the appointment of glasses, you thereby narrow the boundaries of your search and will sooner find for yourself exactly the option that would best suit your individual needs.

Tip 3. Sunglasses performance and recommendations are determined by specifying the category of sunglass filter whose light transmission corresponds to the spectacle lenses. The filter category is usually indicated on the inside of the temple before the “CE” mark (this marking indicates that the product meets European quality standards) and is indicated by a number from 0 to 4. The higher the filter category, the less light transmission of the lenses. The characteristics of filters of different categories are clearly presented in the table below.

Characteristics of filters of different categories

If you need glasses to look spectacular even on the gloomiest day or just hide signs of fatigue on your face, you can easily get by with glasses with a category one filter.

In general, brown, gray and green lenses are considered the most comfortable for the eyes.

Intense tinting of sun lenses does not guarantee UV protection on its own.

Tip 7. If driving on a bright sunny day, you had to get into unpleasant situations due to blinding reflected light, sunglasses with polarized lenses may be the best solution for you (for more on this, see :). They will be useful not only for motorists, but also for those who spend a lot of time outdoors in conditions of excessive solar radiation - on the beach, in the mountains, doing winter sports. The polarizing filter of these glasses allows you to completely eliminate the annoying glare that occurs when light reflects from smooth, flat, shiny surfaces. I would like to make only one amendment regarding motorists: they are not recommended to wear glasses with polarized lenses at night. They reduce the glare of oncoming traffic headlights, but also reduce the amount of light reaching the eye, which is necessary for the driver to ensure safe traffic;

If you've had to deal with dazzling reflected light while driving on a bright sunny day, polarized lenses may be the best solution for you.

Tip 9. If you wear corrective glasses, you can use the following methods to protect your eyes from the sun: you can insert corrective sun lenses into a frame suitable for this purpose, or use sun clips that are worn over corrective glasses. Some companies, such as Polaroid Eyewear, offer clip-on sunglasses with a polarizing filter. To date, there is a wide range of sunscreen clips with various fastening systems, including those with convenient magnetic fastening. From a financial point of view, the clip-on option is more economical than the option to purchase corrective sunglasses.

To date, there is a wide range of sun clips with various fastening systems.

The summer sun gives us a beautiful tan, but ultraviolet light can be dangerous to the eyes. Mankind has long come up with a way out: sunglasses that filter UV rays. Now they can be bought even in the nearest market. But is it worth it? What dangers threaten the owners of cheap plastic sunglasses? What should you pay attention to when choosing reliable protection for your eyes? What do the mysterious numbers and letters in the marking say? MedAboutMe will tell you all about sunglasses with UV filter.

The sun is the main source of ultraviolet radiation (UV). For the inhabitants of the Earth, three main types of UV rays are important in accordance with their wavelength:

• UVA - long-wave radiation, located in the range of 400-315 nm. Makes up about 95% of sunlight. Reaches the earth;
• UVB - medium wave radiation, lying in the range of 315-280 nm. It makes up about 5% of the solar flux. Mostly delayed by the atmosphere, but a small part reaches the earth;
• UVC - short wave UV radiation in the range of 280-100 nm. Almost completely delayed by the ozone layer of the Earth.

The most powerful and dangerous to humans are UVC rays. But because of the short wavelength, they cannot penetrate deep into the skin. The weakest (that is, they can carry the least energy) are UVA rays, but due to their wavelength, they have the maximum penetrating power. They reach right up to the papillary and reticular layers of the dermis, where they activate the processes of melanin formation, that is, getting a tan.

When exposed to the unprotected retina, the sun's rays damage it. As a result, long-term wearing of low-quality glasses in bright sunlight is dangerous for health: it provokes the development of cataracts and retinal dystrophy.

Glasses with filters that protect the eyes from both UVA and UVB rays are marked "UV400", which indicates their ability to filter all UV rays with a wavelength of up to 400 nm. By the way, with the constant wearing of such glasses, a “mask” of non-tanned skin around the eyes forms on the face.

Sometimes there is a label indicating the degree of protection against UVA and UVB rays. For example, "Blocks at least 80% UVB and 55% UVA". This means that the UV filter protects a person from at least 80% of UVB rays and 55% of UVA rays. Doctors recommend choosing glasses where both indicators are above 50%.

Finally, another marking option:

• Cosmetic - Cosmetic UV filters block less than 50% of UV radiation. Such glasses provide little protection from the sun and are not recommended for use on days of maximum solar activity.
• General - universal UV filters protect human eyes from 50 to 80% of the sun's rays, that is, significantly less than half of the dangerous radiation reaches the retina. Glasses with this marking are effective for eye protection in the city, at mid-latitudes.
• High UV-protection - special UV filters that block almost 100% of ultraviolet radiation. Glasses with such lenses are used on a bright sunny day near the water or in the mountains, where water and snow, respectively, increase the danger of sunlight.

Is there 100% UV protection? Glasses with similar inscriptions can be found on the "disintegration" with Chinese consumer goods. No, it doesn't. And such glasses are 100% fake, harmful to health.

The degree of darkness of the lenses (Filter Cat) indicates how much of the visible sunlight reaches the eyes. There are 5 main categories of filters:

• Cat 0 is a lens that is not tinted at all and lets in 100% of sunlight. At the same time, it can 100% protect the eyes from UV rays.
• Cat 1 is a lens that transmits 80% of sunlight. This is a low obscuration filter that can be used in partly cloudy conditions.
• Cat 2 - only 40% of the light passes through this filter. Lenses with a medium-tint filter are used for exposure to not very bright sun.
• Cat 3 - dark filters block most of the sun's rays and let in only 15% of the light. Such glasses are effective for protecting the eyes from the sun in the tropics, by the sea and in the mountains.
• Cat 4 is the most powerful filter, blocking almost 100% of the sun's rays. Such lenses are necessary only for extreme conditions and do not involve wearing them in the city without an emergency. You can't drive a car with these glasses on.

According to Russian standards, prescribed in GOST R 51831-2001 "Sunglasses" and GOST R 51854-2001 "Spectacle sunglasses" also speak of 5 categories of filters according to the degree of light transmission:

• category 0 - transparent filter, transmits 80% of the light flux or more;
• category 1 - slightly colored filter, transmits from 40 to 80% of the light flux;
• category 2 - medium colored filter, 18-43% light output;
• category 3 - dark filter, 8-18% light output;
• category 4 is a very dark filter that transmits 3 to 8% of the light output.

In lenses made of a material that does not protect against UV rays, the protective role is played by a transparent substance applied to the lenses. But by itself, it does not obscure glasses. Therefore, it is important to distinguish between opacity and UV filters. Cheap Chinese plastic glasses can have heavily tinted lenses, almost black, but no UV protection at all. Moreover, experts point out that in such fake glasses, the pupil expands to receive more light - and this increases the area of ​​\u200b\u200bdamage to the eye by UV radiation, which negatively affects health.

Thus, UV filters are needed to protect against the rays of the sun that are harmful to the eyes, and the tint of the lenses makes staying in bright sunlight more comfortable. Photochromic lenses have the ability to change the degree of darkness depending on the light.

Previously, the most popular lenses were made of glass (mineral glass). The alternatives were plastic (organic glass) and a combination of glass and plastic (laminated glass). However, times have changed, new technologies have come.

Among the most popular materials today, the following should be separately mentioned:

• CR-39 (Columbia Resin No. 39) - The original version of this variety of organic glass was first produced back in the 1940s. Today it is one of the most popular monomers in the field of eyeglass lenses. It is softer than glass, so it needs an additional protective coating. In addition, the CR-39 is easily beaten, which is significantly inferior to its competitors;
• polycarbonate (lexan, merlon) - "plastic metal", accidentally created in 1953. It is lightweight and much more durable than glass, meaning it is much safer for the wearer. Polycarbonate has the ability to completely absorb ultraviolet with a wavelength of up to 380 nm, so it practically does not need additional special processing;
• Trivex - was developed in 2000 and modified specifically for optics. It is as impact resistant as polycarbonate; the lightest material currently available in the optical industry; Reliably blocks ultraviolet wavelengths up to 394 nm.