Sunglasses are a must-have item on any clear day. This is not only a stylish accessory, but mainly salvation from harmful ultraviolet radiation. Therefore, it is important to be able to choose the right model and know how the fakes differ from the originals.
What do the numbers on sunglasses mean?
If you look closely and place particular emphasis on certain details, you will notice that on the temples (and sometimes on the glass itself) there are various symbolic notations. Mostly they are a guarantee of quality.
So, here is what responsible manufacturers have on their copies:
- “Made in ...” labels indicate the country in which the glasses were issued. You should beware of those that say “design in”, “frame” or “produced”. There is a high probability that this is not an original sample;
- Encoding of the British standard (BS 2742), German (DIN 58217) or American (ANSI Z80) - says that the model was released in accordance with established international requirements. If the numbers and symbols in such lines are confused or replaced, then you have a "linden" in your hands;
- the letters "P", "RB" or others - symbolize belonging to a particular brand (in this case, "Polaroid" and "Ray Ban"). Often next year is also indicated;
- five digits that do not fit into any of the above categories - the serial number of the product;
- "Filter Cat 2" - this wording reveals the class of darkness. There are four of them (each number indicates a correspondence to a particular group). The first number is assigned to ordinary transparent glasses, and the fourth transmits less than 10% of the light (they are usually chosen by skiers).
Most likely, this entire information on the optics itself will not fit. Therefore, manufacturers attach a special certificate, which sets out in detail all the related data.
And yet, what is the fundamental difference between a fake and genuine sample? As a rule, the former do not fulfill their main function - they do not provide protection against active rays. As a result, besides a spectacular appearance, there will be no benefit from such an attribute. At the same time, the latter guarantee complete safety.
What does uv400 mean in sunglasses
This symbolism requires attention. She tells just about what percentage of UV rays passes through the lenses.
Ultraviolet radiation from the sun (ultraviolet) can be divided into three categories: UVA, UVB and UVC. The rays of the third group will not harm you, since they simply do not reach the earth's surface (they are perfectly retained by the ozone layer). The second and first ones freely pass through ozone and can be absorbed by our body in any quantity. As a result, there is a risk of skin cancer, cataracts, glaucoma, conjunctivitis and other terrible diseases.
UV-A and UV-B radiation have a wavelength range from 280 to 400 nanometers (nm). Hence the inscription "uv400", indicating that the glasses retain light waves up to 400 nm in length.
Reference: specialized models for places or occupations, assuming the presence of active sunlight of high brightness, are designated as "uv600". They are suitable for surfers or climbers.
It turns out that if the labeling contains a smaller number (for example, 380 or 360), then your health is in danger.
Some manufacturers indicate both spectra at once. Often you can find such designations - "95% UVB and 60% UVA". Accordingly, 95% of rays-B and 60 - C are passed here.
And also sometimes such markings are replaced by:
- “Cosmetic” is an ordinary props. Skip more than 50%, serve as a stylish decoration, but nothing more. Use them in high light is not recommended.
- "General" - neutralize up to 80% of ultraviolet radiation. It will fit for the safety of your eyes in the familiar gray urban environment.
- "High UV-protection" - thanks to the strongest filters guarantee a complete prevention of eye diseases. Provide up to 100% protection.
To accurately verify the veracity of the information specified in the certificate (or engraved on the surface), you can ask to check the pair on a special device - a spectrophotometer. Any good store should have one. In just a few seconds you will receive a confirmation or denial of quality.
We must not forget about the importance of such a parameter as color. By and large, the color of the glasses does not matter. The only warning: do not try to get the darkest glasses. Such optics, firstly, will provide you with low visibility, and, consequently, greater tension in the eye muscles, and secondly, will help your pupils to expand. Thus, if you buy a cheap fake optical accessory with black lenses, then it is likely that only exacerbate the situation. A wide pupil unprotected by interference filters will “catch” even more harmful rays. The consequences are not hard to imagine. It is best to pay attention to gray, green or brown colors.
And, in the end, it will not be amiss to ask about the presence of the following additions:
- Abrasion resistant material will not worry about premature aging of glasses. Promotes scratch and crack resistance.
- A polarizing filter or anti-reflective coating provides good visibility without any interference. This feature is important for relaxing by the water.
- Mirror coating completely hides your eyes from strangers. You can watch anywhere, the direction of your gaze will remain a mystery. These lenses fully reflect all the light.
- Melanin on the inside will save you from excessive eye fatigue.
- Gradient color will be especially interesting for motorists. When looking at the road, such optics provide reliable protection from the blinding sun, thanks to the darkened top. At the same time, a light bottom contributes to an excellent view of the dashboard.
Now you can safely go to the store. If you correctly navigate in the labeling, then buying the much-needed part of your everyday look will not be difficult.