What kind of sunglasses are dangerous to health?


What kind of sunglasses are dangerous to health?

And how to choose glasses with high-quality lenses.

reading will take 🕑 3 minutes

The main function of sunglasses, in fact, is the same as that of sunscreens: they must block harmful sun rays. To do this, the lenses are coated with a special coating with UV filters. Without them, even the darkest glass is at least useless.

What are dangerous low-quality lenses

Dark glasses without UV filters create the illusion of protection, but in fact, they do much more harm than good. That's what happens when you wear these glasses: dark glasses reduce the flow of bright light, so pupils dilate - this is a normal reaction to a lack of lighting. Plus, you stop squinting.

As a result, ultraviolet rays freely penetrate not only the skin of the eyelids (hello, photoaging), but also deep into my eyes - which can lead to damage of the conjunctiva (the white part of the eyeball), cornea and retina, as well as to the development of diseases such as cataract, cataract and macular degeneration (loss of central vision). All this is significant, and often irreversible impairs vision.

What should be the correct points

Ideally, lenses should block 99–100% of UVA and UVB rays and be dark enough to screen out 75–90% of visible light.

The colour of the glass does not affect the protective properties (the coating with UV filters is transparent), but the size and shape of the frame matter. The correct glasses are large and with wide arms, that is, they protect the eyes from all sides: from above, below and from the sides.

A separate question - polarized glasses. They reduce glare from a flat, shiny, light-reflecting surface: water, asphalt, snow or crust. To this end, a polaroid film is applied to the lenses in addition to the UV filter. The degree of protection from the sun in such glasses is about 55%, so they can be used as sun-protection in the city, in cloudy or overcast weather.

How to choose the right glasses

Good glasses are always marked with UV400 or UV380. The numbers are the wavelengths of ultraviolet radiation from which the lenses protect. The most dangerous rays are UVA, with a wavelength of 315-400 nm.

Accordingly, UV400 marking means that the lenses protect the eyes by 100%, UV380 - by approximately 95%. Both European standards and  GOST allow the use of glasses with UV380, but it is safer still one hundred percent protection.

You need to look for the abbreviation on the inside of the handle, on the label or package - in short, on what you get with the glasses when you buy (and not on the "certificate", for example, which the seller waved before you).

To understand how well glasses protect against visible light, look for the label “Cat” (category) or “CE” on the label:

  • Cat 0 (or “cosmetic”). Completely transparent, pass from 80 to 100% of visible rays. These are ordinary glasses for correcting vision or, for example, protection from wind. Such marking on chameleon glasses means that they become completely transparent in the room.

  • Cat 1 (or CE0). Pass from 43 to 80% of visible light. Suitable for cloudy weather.

  • Cat 2 (or CE2). Pass from 18 to 43% of visible light. In such glasses, it is comfortable in the city with variable cloudiness and dim sun.

  • Cat 3 (or CE6). Strongly shaded lenses, transmit no more than 18% of visible light. Useful in the city on a clear summer day, and on the beach.

  • Cat 4 (or CE7). Points with a minimum level of transmission of sunlight in the visible spectrum. Designed to protect the eyes where, in addition to the bright sun, there is also a lot of snow (for example, at ski resorts). They can strongly distort the colours, so they are not recommended to get behind the wheel.

Please note that protection from visible light and from invisible UV rays is not the same. Relatively bright (or even completely transparent) glasses can perfectly protect from harmful radiation, if the lenses are equipped with filters.

How to understand that marking is true

Independently, unfortunately, no way. The presence of filters can be checked only on special equipment. Therefore, it is better to buy glasses in optics or “understandable” stores, where the probability of getting a fake is minimal. Sports brands have quite decent (and often relatively inexpensive) options. But the points with the collapse, or, for example, from the resort stores - a lottery, and almost always losing.

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