Learn all about sunglasses: what they are for, what types of protection are used and how to find the perfect glasses.
What are sunglasses for?
Such optics are not just a fashion accessory: goodr green sunglasses protect your eyes from the negative effects of ultraviolet radiation and the literally blinding sun.
UV radiation that is harmful to humans is divided into two types – UVA and UVB. The first type can damage the retina of the eye and provoke the process of vision loss. Such rays accelerate the aging process of the skin and are often the cause of skin cancer. The wavelength of UVA radiation reaches 400 nanometers.
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Rays of the second type – UVB – are not so dangerous for the eyes, however, with intense exposure, they can also affect the deterioration of vision, causing clouding, pain, and temporary blindness. The wavelength of these rays reaches 315 nanometers.
To protect the eyes and skin of the eyelids from the negative effects of ultraviolet radiation, it is necessary to use sun-protection optics – it is equipped with the necessary filters that perform a barrier function and prevent the penetration of harmful rays through the lenses of the glasses.
At the same time, sun protection is equally important – in bright sunny weather, we squint more, and this can lead to headaches. In addition, the eyes can overstrain due to increased stress. Using prescription sunglasses online cheap help you to fight this.
Seasonality of sunglasses
Ultraviolet radiation does not depend on the season. In winter, the sun’s rays are reflected from the snow and cause no less harm to the eyes than on a fine summer day. In cloudy weather, vision also needs adequate protection, since the clouds blocking the sun’s rays freely let in UV radiation. This means that you need to protect your eyes all the time, the main thing is to choose glasses in which the degree of shading corresponds to the season!
Who needs to wear sunglasses?
Everyone needs sunglasses, regardless of age, gender and even lifestyle. First of all, experts recommend this accessory to people who spend a lot of time outdoors, people with high sensitivity to bright light, patients with glaucoma and other diseases of the organ of vision, as well as young children, for whom ultraviolet radiation is more destructive than for adults.
How to choose glasses according to the type of protection?
Pay attention to the labeling of the glasses. Only lenses with a UV-400 mark will provide 100% UV protection – they completely block the penetration of UV radiation. The lower the number on the label, the weaker the protection. It is also possible to indicate protection against specific types of rays, i.e. UVA and UVB.
There is another marking: from 0 to 4, where 0 is only 5% protection from UV rays, and 4 is 95% protection. This marking can also indicate the degree of darkening of the lens.
To maximize the safety of your vision, it makes sense to take care of buying glasses with different types of lenses. For example, in cloudy weather, it is worth protecting your eyes with clear lenses or glasses with a gradient.
Are all sunglasses useful?
Alas, not all glasses are equipped with the necessary filters that protect the eyes from ultraviolet exposure. Although today even among cheap models you can find high-quality sun-protection optics, Chinese fakes still occupy a certain market share.
Such glasses not only do not protect your vision but also cause additional damage to it: due to the tinted lenses, the pupil is constantly dilated, as a result, even more, unfiltered sunlight enters the eyes than without glasses. And prolonged exposure to UV radiation damages the retina and leads to a significant deterioration in vision.
How to test sunglasses at home?
If you want to make sure your goggles are adequately protecting your eyes, use an ultraviolet flashlight, which you can easily buy online. The average cost is about 300 rubles.
If the glasses have UV filters, the flashlight will not shine through the lenses and the shadow from the glasses will be complete as if it were a solid structure. If you got low-quality optics, only the frame will cast a shadow, while the lenses will quietly let in the light from the flashlight and, accordingly, harmful radiation.
Does the material of the glasses matter?
When it comes to spectacle lenses, they are traditionally made of two materials – glass or plastic. It is believed that among cheap models, preference should be given to glass lenses, as they are more often equipped with UV filters.