How to escape from the "hares". Instructions for combating ultraviolet

Once in the distant school years, I had the idea to do auto-restoration, since my father already had almost rotten (but with an excellent engine) AZLK 3r334. Moskvich-408
. First of all, of course, it was decided to change the thresholds and strengthen the frame with a metal channel. The fastest way - naturally welding, the benefit of his father and a homemade machine on the W-shaped plates was. I found the electrodes and, in principle, pretty well welded pieces of metal. Satisfied with my work, I fell asleep, thinking that I would be welding in the morning. And in the morning I woke up and realized that I was “blind”, and my father congratulated “on the first hare caught”. To understand what the conversation is about - follow the cut.
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3r311. 3r369595. “Rock hares” , well, then everything ended more or less safely, the familiar men recalled their experiences of familiarity with the welding business, my mother felt sorry for and buried in her eyes 3r-3551. chloramphenicol vs lidocaine 3r3-3552. . And I was thinking about what blind people are like to read articles and work with a computer, and I’ve already wondered about a draft of an article on this topic. But the young body is recovering quickly, and by the end of the second day, some everyday thoughts again occupied the head.
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 3r3694. The second time I ran into the “hares” when I listened to the stories of one of the old mountain tourists about snow blindness. As an example, Dedok cited the comparison that they say "mountain blindness is the same as from welding to catch hares" (yes, the very same ones). It was then that I finally got around to deal with such a rather dangerous eye disease as photokeratitis and find out that “ultraviolet” is far from being only a “source of vitamin D” (3r-3587. Not all yogurts are equally useful. 3r-358.).
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 3r3694. Several times in the electrotechnical department of our central department store TsUM personally heard from people questions to the sellers "and you do not have UV lamps ?!", "but where to buy a UV lamp?", Etc. As it turned out later, people need ultraviolet light lamps for completely different reasons - someone to “treat the parrot” (???), someone wanted to “watch the minerals”, there were those who tried to start the UV treatment of water or determine skin diseases Wood's lamp.
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 3r3694. And this means that people quite actively use ultraviolet, adding to themselves bonuses to solar radiation. Moreover, it is natural not to use any protection at all. After all, the Internet says "do not be afraid, the glass will delay." And these poor fellows are sitting in ordinary glasses. Using the fact that Habr is indexed well, I decided to write a small tutorial on the basics of security (3r-3587. And at the same time encourage my pharmaceutical diploma, and then I write everything about routers, even lab technicians laugh at 3r-?588.). Since I myself was looking for information on UV protection and did not really find anything (I went to the mountains with glasses from some Soviet device).
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 3r3694. 3r33575. A few words about the classification of the ultraviolet and its sources 3r33535.
 3r3694. Just in case for those who knew yes forgot, a little Wikipedia :
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Ultraviolet radiation (ultraviolet rays, UV radiation) - electromagnetic radiation occupying the spectral range between visible and X-ray radiation. The wavelengths of UV radiation lie in the range from 10 to 400 nm (7.5 · 1014-3 · 1016 Hz). The term is derived from lat. ultra - over, outside and purple (violet). In colloquial speech, the name “ultraviolet”
can also be used.
How to escape from the "hares". Instructions for combating ultraviolet  3r3694. According to the ISO-DIS-21348 standard, ultraviolet radiation is divided into several subtypes (it is noted that 3r33333. Abbreviations 3r3634., Can be useful when selecting UV LEDs on aliexpress):
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3r3633. 3r369595.
 3r3694. All existing sources of ultraviolet radiation (hereinafter UV) can be divided into natural and artificial. The main source of natural UV is the sun. Of the total solar radiation, the earth’s surface reaches only its long-wavelength part (~ 3-4% of the total energy of solar rays). Shortwave, fortunately (why “fortunately” is described further), is delayed by the atmosphere. Therefore, for the far and extreme UV range, the term “vacuum” (VUV) is often used, meaning that it is impossible to meet it on Earth under normal conditions.
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 3r3694. In addition to the sun, a huge number of sources of UV is of artificial, man-made origin. These include laser installations (operating in the UV and “vacuum” UV ranges), electric arcs arising from welding, plasma, molten metal, and similar objects having a temperature of> 2000 ° C. UV also emit some metallurgical furnaces /blast furnaces for the smelting of high-temperature metals and alloys using oxygen blast, powerful electron and plasma flows, etc. A fairly intense source of UV with a continuous spectrum are electron fluxes of synchrotrons, linear accelerators, and high-power microwave devices. Emit UV and mercury rectifiers - ignitrons (by the way, incredibly beautiful, in my opinion, devices).
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 3r3694. But the most common (third-third, after the Sun, 3-33588.) Source of man-made UV are all kinds of lighting devices — luminescent light sources (gas-discharge and mercury lamps) and, more recently, LEDs.
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 3r3694. They emit UV without exception, the only difference is in the power and proportion of UV radiation relative to other types of radiation. There is a share of UV in the "light bulb Ilyich", which today has practically disappeared from the houses. In its spectrum, UV accounts for less than 0.1% (although the fraction increases with heating of the lamp). It is logical that for various medical and technological applications such a source will not be enough. That is why, for the needs of science and art, most of them use lamps filled with mercury vapor: lamps of high (150¸400 mm Hg) pressure using an arc discharge, and lamps of low (???¸1.0 mm of mercury). a) pressure using a smoldering charge. There is truth, however, and lamps of ultrahigh (> 1 atm) pressure, but they are rarely used. In the flasks of the lamps there are mercury vapor (or even drops of metallic mercury, which evaporate when heated), which under the influence of an electric discharge goes into an excited (*) state and begin to radiate intensively in the UV region. The principle of operation is shown on scheme 3r3683. . Functional differences are only in the circuitry of ignition, charge maintenance, etc.
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3r3-300. 3r369595.
 3r3694. Those. in the absolute majority of lamps of various functional purposes the same principle is used. The functional is formed at the stage of passing UV radiation through glass. In the simplest application, it turns out that if the UV passes completely - we get a quartz lamp, the radiation is completely delayed by the phosphor on the walls of the flask - we get a fluorescent lamp, the radiation is selectively filtered at a certain wavelength - we get some 3r3104. UV lamp for catching mosquitoes
.
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 3r3694. From the above it follows that the main component responsible for the range of waves that the lamp emits is the glass envelope (“bulb”) of the lamp, more precisely the chemical composition of the glass from which it is made.
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 3r3694. By changing the characteristics of glass, manufacturers are making the manufacture of devices capable of creating radiation in a strictly specified wavelength range, optimal for certain purposes. For example, when creating germicidal lamps, so-called. 3r33333. Uviol glass 3r3633. (from lat. ultra - outside, on the other side, above and lat. viola - violet color). Its main feature is that upon receipt, the presence of coloring impurities that absorb the ultraviolet of Fe is minimized. 2 3r3141. O 3 3r3141. , Cr3r3140. 2 3r3141. O 3 3r3141. and TiO [sub] 2 3r3141. . In the so-called “bezosonovye” bactericidal lamps it is used titanium oxide TiO 3r3-33140. 2 3r3141. which selectively absorbs ultraviolet with a wavelength of 180 nm (this UVC ionizes oxygen with the formation of ozone).
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 3r3694. The same principle works for other wavelengths. For example, to create a Wood lamp (“disco UV”) with a transmission maximum in the range of 368–371 nm, a uviol glass bulb is used in a very dark, blue-violet color, which is formed by adding cobalt /nickel oxide (NiO /CoO content around 9%). Instead of violet glass, a phosphor based on europium doped strontium borate can also be used (SrB 3r3-33140. 4
O 3r3-33140. 7
: Eu 2+ ), While for receiving radiation in the range 350-33? 3+ [/sup] lead-doped barium silicate (BaSi 3r3-33140. 2
O 5 : Pb 2+ ).
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 3r3694. The picture below shows 3r3148. standard compositions 3r3683. and the corresponding wavelength.
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 3r3694. As LED sources, I can act as LEDs (where now without them in the 21st century). True to achieve such a narrowband, as in fluorescent lamps is not yet possible. Most of the existing solutions operate in the wavelength range> 380 nm, and there you can reach 400 nm by hand. Those. on aliexpress for a couple of dollars the maximum that can be bought is the LEDs of a beautiful, but still visible, purple range. Therefore, all sorts of penny "disinfectants" ( water, inhaled air, rooms, keyboards, etc., thousands of them) will not work. The most interesting thing is that in the last 5-7 years there have been exceptions in the world of LEDs that can generate a real, and even hard UV (killing bacteria, also “254 nm”). The picture below shows these semiconductor analogues "Mercury lamp" (of course, adjusted for power, but I'm tied to the wavelength), with a net 245 nm, and the cost of some 300 euros (~ 100 conventional UV can be bought for the money).
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3r3r1616. 3r369595.
 3r3694. Who does not like the LED for 300 euros, you can try the LED for $ 140.
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 3r3694. 3r3662. 3r3663. Cheaper, but smd [/b] 3r36565.
3r3179. 3r369595.
 3r3694. Sells their hot favorite ThorLabs. True it is 3r3183. UV LEDs
UVC range (280 nm at the peak), but you should not be upset, because according to the guidelines of the sanitary and epidemiological regulation of the Russian Federation, it is believed that ultraviolet radiation with a wavelength range of 205-315 nm has a bactericidal effect (see the picture in the beginning of the article) with the signature "Spectral curve of destruction of the genetic apparatus of microorganisms").
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 3r3694. In general, what can I say. And the fact that due to differences in the production technology of glass (and /or output control) a fluorescent lamp can produce a different wavelength range. The phosphor tends to fade, shatter, etc. over time. etc. This means there is a possibility that the cause of a burning sensation in the eyes may be not only increased corneal dryness, but also UV burn (see the section on biological effects). So, reader, support in a friendly manner the transition to LED lamps, even if they want to, they are unlikely to squeeze an “adult” UV out of themselves.
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 3r3694. 3r33575. Application. Art and science
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The most beautiful thing we can experience in life is mystery. It is the source of all true art or science.
 3r3694. Albert Einstein
It is hard to write about the use of UV, because it is very, very extensive (and as a rule, those who apply, know what they use, and when they do not know, they guess). In the spoiler I will hide references to books in which you can read about it.
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 3r3694. 3r3662. 3r3663. References for the study of 3-333664. 3r36565.
Meyer A., ​​Zeitz E. Ultraviolet Radiation, trans. with him., M., 1952
James R. Bolton, Ultraviolet Applications Handbook, Bolton Photosciences, 2010
James R. Bolton, Christine Colton, The Ultraviolet Disinfection Handbook, American Water Works Association, 2008
Larry J. Forney, Carmen I. Moraru, Tatiana Koutchma Ultraviolet Light in Food Technology: Principles and Applications CRC Press, 2009
Ahmad I. Shamim, Ultraviolet Light in Human Health, Diseases and Environment, Springer, 2017
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 3r3694. It is important to note that the scope of application In most cases, they are tied to one or another frequency range of UV. In its simplest application, it looks like this:
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13.5 nm: photolithography in the deep ultraviolet
30–200 nm: photoionization, ultraviolet photoelectron spectroscopy (UPS), production of electronic components using photolithography
230–365 nm: UV-ID, tag tracking,
bar codes. 230-400 nm: optical sensors, various tools
240–280 nm: disinfection, disinfection of surfaces and water (DNA adsorbs UV with a wavelength of 260 nm)
200–400 nm: forensic analysis, determination of drugs
270–360 nm: protein analysis, DNA sequencing, drug detection
280–400 nm: medical imaging of cells
300–320 nm: phototherapy in medicine, 3r3694. 300–365 nm: curing of polymers and printer inks 3r3-3694. 350–370 nm: insect traps (most insects are sensitive to UV with a wavelength of 365 nm)
 3r3694. Much more spectacular than any VUV photolithography is the use of UV in areas associated with visualization (i.e., transfer to a format that is accessible to the eye). This possibility is based on the fact that, due to high energetic fullness, UV photons can transfer atoms of many organic and inorganic compounds to the excited (*) state and thereby cause the luminescence phenomenon, i.e. non-thermal glow (as a rule, in the visible range, which is why all of this is so appreciated by our eyes, which are not too sensitive to other ranges).
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 3r3694. From the most nice things you can remember, for example, the glow of minerals and rocks. This phenomenon has been known for quite some time and has been actively used in mineralogy, geology, and mining for express detection (3r-3247. Such 3r-?683. Small lamps are used for this).
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 3r3694. Thanks to the Internet, the amateurs can share their impressions, which they gladly use by laying out photos of precious, semi-precious and ornamental stones glowing in the UV rays (topaz, for example, glows bright green, emerald - red, pearls - gives a rainbow picture .d.) You can read more (and see pictures) here , here and here
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 3r3694. Another wonderful (yes, what a fabulous one is here) is obtained by lighting up different flowers with UV. In plants there are many complex organic compounds that happily share their luminescence with the viewer. And since the location of the compounds is completely disordered, the pictures are fantastic. The photographer actively exploits this topic in his works. Craig P. Burrows 3r3664. :
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works. 3r36565.
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 3r3694. UV luminescence is actively used in cosmetics and others like them. purposes. On sale you can find a lot of glowing cosmetics and paints for application to the body . Although the “tint” of an insufficiently clean (or weakened) organism can also be bacteria /fungi and other disease causing microflora, which also contains substances capable of luminescence. A rather well-known method of rapid diagnosis called 3r-36566 is based on this feature of microorganisms. lumdiagnosis [/b] or Diagnostics lamp Wooda . The technology is simple, accessible even to the uninitiated user (with a subsequent, naturally attendance to the doctor) and therefore is actively used in dermatology, cosmetology and veterinary medicine, for the rapid determination (moreover, quite accurate) of various pathologies on the skin. The point is that in the UV, in the range of 360-370 nm, many waste products of fungi, bacteria and microparticles of toxins give a clearly visible bright glow of various shades. In order not to be intimidated by the details, I'll hide it under the spoiler.
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 3r3694. 3r3662. 3r3663. Fluorescence of skin diseases in Wood's soft UV lamp. Details 3r36464. 3r36565. Bright fluorescence is given by fungal infections of the skin and hair thanks to pteridine. In this regard, a green-blue, light yellow, light-blue glow of skin and hair scales can serve as an alarm. Similar fluorescence is caused by infection with Pseudomonas aeruginosa, since pathogenic Pseudomonas produce pigment pyoverdin or fluorescein, which exhibits green fluorescence in the beams of the Wood lamp. Light blue glow indicates normal healthy skin, intense blue color indicates increased dryness of the skin. Violet is a sign of sensitive skin. Inflamed areas of tissue can be recognized by the white color of the luminescence, however, if it is barely distinguishable, then the probability of ordinary contamination is great. Brown light occurs when there is pigment, which is used in the diagnosis of depigmentation and hypopigmentation, and green or yellow-green - with fungal skin lesions. Multi-colored lichen gives a dull yellow luminescence, erythrasma - pink or red, favus - light silver, microsporia - yellow-green (emerald) fluorescent, favus-frosted silver, erythrasma - pink, brick-red glow, otrubodnoobrazno-silver or brown. luminescence, rubrofitia - coral-red luminescence, lupus erythematosus - white or dull-white luminescence, leukoplakia - green luminescence, cancer - red luminescence, KPL - yellow-brown luminescence, leptotrichosis - yellow luminescence, candidiasis - snow-white luminescence, cocco Vaya flora - purple glow, cocci + Candida - orange glow, vitiligo - depigmentation is more pronounced and has a shade of silver-blue, vascular nevi - depigmentation is absent when viewed in the rays of the Wood lamp. Moreover, luminescent diagnostics of microsporia (ringworm), microtoxins, fungal lesions should be used in complete darkness.
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 3r3694. As follows from the above, UV simply cannot fail to arouse idle interest among a wide circle of readers of 3r-3587. and naturalists 3r33588. . Find the lamp, turn on and watch the effect - the first thought. But about the defense, in most cases, remember when it's too late. Therefore, we are moving towards the main goal of the narrative, for the disclosure of which it is still worth mentioning about some important biological effects of UV.
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 3r3694. 3r33575. Biological effects: the benefits and harm of 3r-3576.
 3r3694. About the benefits of UV can probably be able to tell a lot of visitors tanning salons and those who have overcome the lack of vitamin D3 in the body. Actively working on the promotion of UV as a therapeutic physiotherapy procedure in the USSR, mandatory UV baths were even introduced into the cosmonaut’s life program outside the Earth. Therefore, I will simply quote Wikipedia (3r33939. RU 3r3683.):
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It has been convincingly proven in hundreds of experiments that radiation in the UV region of the spectrum (290-400 nm) increases the tone of the sympathetic-adrenaline system, activates defense mechanisms, increases the level of nonspecific immunity, and also increases the secretion of a number of hormones. Under the influence of UV radiation (UV rays), histamine and similar substances are formed, which have a vasodilating effect, increase the permeability of skin vessels. Changes carbohydrate and protein metabolism in the body. The action of optical radiation changes pulmonary ventilation - the frequency and rhythm of breathing; gas exchange, oxygen consumption increases, endocrine system activates. Particularly significant is the role of UV radiation in the formation of vitamin D in the body, which strengthens the musculoskeletal system and has anti-chitin effect. It should be noted that long-term failure of UVI can have adverse effects on the human body, called "light starvation." The most frequent manifestation of this disease is a violation of the mineral metabolism, reduced immunity, fatigue, etc. Somewhat later, in the works (OG Gazenko, Yu.E. Nefedov, EA Shepelev, S.N. Zaloguev, N.E. Panferova, I.V. Anisimova) the specified specific radiation effect was confirmed in space medicine . Preventive UV irradiation was introduced into the practice of spaceflight along with the Methodological Guidelines (ME) of 1989 "Preventive ultraviolet irradiation of people (using artificial sources of UV radiation)." Both documents are a reliable base for further improvement of UV prophylaxis.
And now about the harm. As I mentioned above, the DNA of bacteria is sensitive to UV in the range of 240-260 nm, so this range is most often used with bactericidal properties. Human DNA, by the way, has a similar sensitivity :). It is just that the bacterium is small, and the person is large. It will take longer to process the effect. But seriously, UVA and UVB radiation can cause cell damage, leading to their programmed death, not to mention the various free radicals, etc. The picture below shows schematically the scheme of DNA damage by high-energy UV photon. In short, the most common occurrence of thymine bases and their binding to each other in the dimeric structure, which leads to a distortion of the DNA molecule and, accordingly, the loss of some part of the functionality.
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3r33350. 3r369595.
 3r3694. In general, the effect of radiation on various organs and tissues is presented quite clearly in the picture. Even to people who are not familiar with the English language it will become clear that the eyes take the brunt of themselves when meeting with UV, although the skin also gets it.
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 3r3694. The image below shows a “living” effect of radiation on the skin. It is known that with increasing frequency the photon energy increases, and hence the damaging effect. But at the same time as the frequency increases, the depth of penetration decreases. As a result, the shortwave spectrum (bactericidal) causes severe superficial burns, and the longwave spectrum penetrates deep into the skin, causing damage and mutations in the growth zone. This range is responsible for photo-aging and potential oncology.
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 3r3694. The following picture clearly shows how deeply it penetrates and how well UV is absorbed by various structures and tissues of the eye.
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 3r3694. Moreover, it is interesting that with age, the susceptibility of the eye to various types of radiation changes. Under the spoiler - illustrative examples (taken 3r36666. Hence 3r3683.).
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 3r3694. 3r3662. 3r3663. Test find the range of waves that suits you! 3r3664. 3r36565. 3r33333.
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 3r3694. The most common in the modern world - the neighbor, the so-called. "Soft" UV long-wavelength range (315-400 nm). Looking at the scheme, it is clear that this range is almost completely retained by the lens (especially in people of middle and old age). This effect is clearly visible if you look into the eyes of a person while in an institution full of decorative UV lamps.
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 3r3694. 3r3662. 3r3663. Luminescence of the lens in soft UV 3r3363664. 3r36565.  3r3694. 3r369595. 3r369595.
 3r3694. Of course, the intensity of the radiation of such lamps is not too high to cause fatal damage, but, as you know, a drop wears away a stone. Plus, most often “decorative UV” is used in combination with dimming (lack of lighting) ~ dim light =>[s] “The diaphragm is open” 3r33588. the pupil is maximally dilated => the maximum possible /available UV acts on the eye. As they say, DNA cannot damage it, of course, but
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 3r3694. If suddenly it is interesting to someone that it is in the structure of the eye that it reacts /is damaged by a certain wavelength, then a table of correspondences will be of help. We find our interest further in the ophthalmological dictionary for decoding.
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 3r3694. Table - Interaction of light with eye tissues and chromophores (taken From here And translated]
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 3r3694. 3r? 3551. Note: SWS 3r36464. = S-type “cones” are sensitive in the violet-blue (S from the English. Short - short-wave spectrum) part of the spectrum; 3r3656. MWS 3r36464. = M-type cones - in the green-yellow (M from the English. Medium - medium wave) part of the spectrum; 3r3656. LWS 3r36464. = L-type "cones" - in the yellow-red (L from the English. Long - long wavelength) part of the spectrum. 3r33552.
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 3r3694. 3r33575. "What was there? How did you escape? ”- about the spectral protection of the eyes against UV 3r33535.
 3r3694. Over the centuries of human existence, people by trial and error have learned with grief in half to defend themselves from solar radiation, someone changing the amount of melanin in the skin and rapidly blackening, and someone using umbrellas and long-haired hats. Heinrich Saulovich Altshuller in its ARIZ-85B, when considering problems, it teaches us to take examples from another technical field, where this problem has been solved more successfully. In the case of protection from UV - such areas, in my opinion, can act as mountaineering and welding. From the welders you can take note of their dense hb suits and leggings (as far as is permissible, of course). In principle, any fairly dense dark fabric perfectly protects exposed skin from UV radiation due to adsorption. But it will be hotter :) and minimize the risk of multiple reflections (about them below). With the protection of the eyes during welding, everything is also in order, but it’s too ugly (shield and masks look like this well I think everyone knows how they look). Better like this: 3r3684.  3r3694.
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 3r3694. Therefore, when talking about protecting your eyes from UV, it is best to use the mountaineers' equipment. And not only them, by the way. In mining engineering and practice, the radiation burn of the eye is usually called the term "3r33466. Snow blindness
".
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Snow ophthalmia or snow blindness - a burn of a conjunctiva and a cornea of ​​an eye ultraviolet rays of the sun reflected from snow crystals. Especially often occurs in spring, in the period of "snow shine", when the reflectivity of snow cover increases.
Moreover, long before the emergence of mountaineering and mountain tourism, indigenous peoples living in the regions of the Far North, Alaska, etc., came across this phenomenon. And they found their solution - glasses with narrow slits . With this approach, parasitic exposure (i.e. those reflections) in the eye is completely minimized.
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 3r3694. In mountaineering, such glasses were also used (and can be used now, as a reserve, if any suddenly broke. Julbo Sherpa ). But of course the convenience and visibility does not add such a configuration. This is what V. Shimanovsky advises on this in his famous book Dangers in the Mountains: 3r3684.  3r3694.
To protect the eyes from burns, it is necessary to use goggles, whose dark glasses (orange, dark purple, dark green or brown) absorb UV rays to a significant extent and reduce the overall illumination of the area, preventing eye fatigue. It is useful to know that the orange color improves the feeling of relief in conditions of snowfall or a little fog, creates the illusion of sunlight. Green color brightens the contrasts between brightly lit and shady areas of the terrain. Since the bright sunlight reflected from the white snow surface has a strong stimulating effect on the nervous system through the eyes, wearing protective glasses with green lenses has a calming effect. The use of goggles made of organic glass in high mountain and ski travel is not recommended, since the spectrum of the absorbed part of ultraviolet rays from such glass is much narrower, and some of these rays, which have the shortest wavelength and have the greatest physiological effect, still come to the eyes. Prolonged exposure to this, even a reduced amount of ultraviolet rays, may eventually lead to burns to the eyes.
Before going to the materials directly from which the lenses are made, I would like to draw attention to the fact that the peculiarity of good mountain glasses is that they also protect against side illumination. It is wrong to think that UV gets into the eyes only in a straight line, most of which still accounts for various lateral reflections and reflections. The reflection of UV from the surface, called albedo, in my opinion is a very underestimated source of radiation. Under the spoiler there is a large informative picture that will help to understand it, using the example of solar UV, although anybody can be reflected.
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 3r3694. 3r3662. 3r3663. UV cycle in nature
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 3r3694. In principle, in the modern city, with its abundance of mirror surfaces and glossy building materials, the situation with the reflections is not much better than in the mountains. Under the spoiler, just in case, there is a plate of reflection indicators for different materials (incidentally, snow is leading):
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 3r3694. 3r3662. 3r3663. The tendency of various materials to reflect UV [/b] 3r36565. 3r???.
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 3r3694. And how it all gets into the eye, bypassing the glasses, you can see under the spoiler. The moral is that the glasses should fit snugly to the face (this is more often observed in the so-called "3-33521. Rifle tactical glasses 3r3683.", About Alp, silent, because they are expensive. Various "fashionable" and elaborate modifications - most often simply useless 3r3-33633. at least 3r3634. due to non-ergonomic design.
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 3r3694. 3r3662. 3r3663. The essence of the futility of Wrong sunglasses 3r366464. 3r36565.
3r? 3534. 3r369595.
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 3r3694. Now about the materials from which the points are made. As mentioned in the chapter on the classification of UV sources, the main thing that makes any fluorescent lamp a UV lamp is the glass from which the bulb is made. The same statement applies to points. In fact, glasses are a common optical filter. In theory, filters for UV can be solid, liquid and gaseous. Naturally, for use as a basis for the lenses of glasses can be used either glass or some of the polymers. Below is a picture from the journal "Chemistry and Life" (198? №? with. 47–51) which quite clearly illustrates the filtering ability of various materials with respect to UV
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 3r3694. 3r? 3551. Note: 1-optical quartz 3 mm; 2- 2.5 mm plexiglass; 3 - window glass 1 mm; 4 - window glass 5 mm; 5 - polyester film of ??? mm; 6 - polyvinyl chloride film ??? mm 3r33552.
 3r3694.
 3r3694. From the graph it follows that common materials (almost all) can filter shortwave UV. But shortwave UV is quite rare in our area, only in hospitals, and when working with UV-erasable memory chips (and these now still need to be found). Polycarbonate (PC), which is widely used for creating glasses, is absent on the graph, but nevertheless, without additional sprays, it perfectly passes UV to 300-350 nm. And how to find out if there is sputtering there or not (especially in the case of glasses purchased on Aliexpress) - I will try to explain further.
 3r3694.
 3r3694. In general, if the sellers say that the glasses do not let in UV - they most likely do not dissemble, but I hope I have explained quite clearly why it is important to clarify WHAT THE UV does not miss the glasses. There are many ranges, the prevalence in the world around is different. On the beach, glasses that delay "bactericidal", but miss the long-wave - will bring harm. At one time, the [b] badge was a rather convincing argument for buying points. UV400 3r36464. which confirmed that the lens used in glasses protects against all rays with a wavelength less than 400 nm (and this is just the ultraviolet range). Another 95% UV badge can be found, which means that the lenses absorb 95% of UV rays. The Chinese joyfully stamp these badges wherever they lazy, demand creates supply. A few manufacturers can offer a certificate of quality, where it will be indicated that the lens really delays such and such a range.
 3r3694.
 3r3694. If we are already talking about plastic “fake” sunglasses (which parents often buy for their children in the nearest stall), then I would like to point out the following thing. As I already mentioned, in bright light, our pupil automatically shrinks, helping the lens to protect the internal structures of the eye from UV exposure. And in dark glasses with poor-quality lenses, the pupil “works falsely” and expands, allowing an excess dose of radiation to pass through. So it’s better to do without cheap sunglasses at all by closing off some Afghan from the sun
 3r3694.
 3r3694. By the way, a small addition. As can be seen from the graphs depicting the spectrum of sunlight, blue-violet, blue and blue waves (400-500 nm) are adjacent to the UV, which can also have a detrimental effect on the structures of the eye, albeit to a lesser extent (see nameplate "The interaction of light with eye tissue and chromophores"). Therefore, from the point of view of spectral protection, the most optimal are those glasses whose transmission range of 400-500 nm is 2-3 times lower than the transmission of the green-yellow-orange components (500-630 nm). Those. “jolly” yellow /orange /brown than blue /green /purple will be much healthier.
 3r3694.
 3r3694. 3r33575. And what follows from all this? 3r33576.
 3r3694. What follows is that thanks to our vision we get 90% of the information about the world around us. This is, in principle, the most important of our "sensors of the world." And it just needs to be treated as carefully as possible. In summer wear wide-brimmed hats, use normal (see above) safety glasses when working with ultraviolet light and constantly check sunglasses for their protective properties.
 3r3694.
 3r3694. The easiest option is to adhere to (= search on the manufacturer’s website) safety standards, in particular, American ANSI Z80.3-1986 (in which UV-protected glasses must have the prefix U and some kind of digital index, from 2 min to 6 max). There are the same parameters and Germany (DIN), UK (BS), Australia (AS). Let the thing (especially the child) be more expensive, the children will grow up and will say thanks for it, if not with words, so with their deeds and achievements. Minus - in cost.
 3r3694.
 3r3694. The more difficult option is to test 3r3-33587 pedantically. Check for lice Chinese glasses 3r33588. purchased glasses, especially on UV permeability. The scatter of materials (and sellers) of which make glasses is simply huge, it is not possible to track everything just by reading advertising brochures. So, in any case, it is necessary to resort to specialized devices (most likely self-made). The main difficulty in checking - in the presence of a source of ultraviolet radiation. In this case, can help out any stall selling accessories for nail.
 3r3694.
 3r3694. 3r3662. 3r3663. Cheap UV lamp at 365 nm from matches and acorns 3r3-3664. 3r36565. A small life hack, for those who need a compact UV lamp for scanty money. For some reason in our area it is incredibly difficult to find a UV lamp (near, far, yes any UV subrange) with a standard "convenient" base. In my case, this is E27. Moreover, disinfecting lamps with G23 base (like Osram Puritec HNS S 7W) and cheap Chinese “for nails” are actively sold.
 3r3694.
 3r3694. It all started with the very lamps for curing nail polish. Consultants who sell them completely out of topic, why there are two types of lamps with the letter L and without the letter L at the end - UV-9W and UV-9W-L. Motivate by the fact that for each type of device (manicure "trick" this has already become a device) - you need your own lamp. I did not have such a device, I connected it to a standard telescopic desk lamp. Nothing worked and had to figure it out. It turns out all quite simple. The lamp in the letter L has a ballast in the form of an ordinary neon lamp (such a lamp can be connected to a desk lamp), without the letter L - the lamp has a soldered capacitor inside and requires electronic ballasts to run. Electronic ballasts are easily obtained from CFLs (9 ~ 12 watts) in 90% of cases, their malfunction is connected with the filament breakage, and not with faulty electronics 3r3684.  3r3694.
 3r3694.
 3r3694. Solder the lamp contacts from the plug and solder to the electronic ballast of close power. Everything works, but for such manipulations, G5 /2G11 /G13 lamps are better suited for where all the contacts from the filaments are already brought out to the connector.
 3r3694.
 3r3694.
3r3615. 3r369595.
 3r3694.
3r3620. 3r369595.
 3r3694.
3r33625. 3r369595.
 3r3694. 3r369595. 3r369595.
 3r3694. In addition to the lamp, you need any UV fluorescent mark (a smear of "glowing" lipstick or foundation at the end). By the way, the LEDs used in modern lighting lamps can also act as indicators. 3r33333. UPD: 3r3634. User varnav He reasonably remarked that a dollar bill could also act as a tag. We place our improvised UV sensor under the glasses and illuminate the UV glasses. Watching: 3r3684.  3r3694.
 3r3694.
 3r3694. The label is lit - glasses do not fit. And so - until a satisfactory result is obtained (it may well turn out that after 10-15 such experiments, it will be easier to give hard $$$ for high-quality UVEX /3M, etc.).
 3r3694.
 3r3694. 3r3656. On this all, take care of your eyes, yours and loved ones! 3r3664.
 3r3694.
 3r3694. 3r3656. Thanks 3r3664. : the author is grateful to his wife - a source of inspiration and search interest in fluorescent UV lamps :)
 3r3694.
 3r3694. 3r3662. 3r3663. USED ​​REFERENCES 3r3-33664. 3r36565. 3r3666. www.researchgate.net/publication/261544037_Health_Effects_of_Artificial_Light
 3r3694. 3r33670. Photoprotection of the eye - UV radiation and sunglasses
 3r3694.
 3r3694. 3r3678. Natural UV-B radiation therapy received by people for outdoor use, indoor radiation, and UV-B treatment of psoriasis
 3r3694. 3r38282. www.researchgate.net/publication/16798031_Clinical_Climatology
 3r3694. 3r369595. 3r369595. 3r369595. 3r3694. 3r3694. 3r3694.
3r3694. 3r369595.
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