It is impossible to imagine the image of a stylish young and modern woman without fashionable sunglasses. This accessory is available for every girl – and, as a rule, not in a single copy. But the main task of sunglasses is not to correct the image of a successful woman – but, first of all, to protect the eyes from the sun. Therefore, the choice of this accessory should be more careful.
How to choose the right goggles to protect from the sun, and what do we need to know about the degree of shading?
We are studying the issue!
The content of the article:
- The choice of lenses – glass or plastic?
- Sunglasses with UV filter, degree of protection
- Lens Shade – Filter Cat
- What color of glasses should I choose?
- Frame and vision – is there a connection?
- Prescription sunglasses
Choosing sunglasses lenses – glass or plastic?
Before heading to the store for glasses – decide which lenses are preferable for you, made of plastic or glass?
- Plastic: durable, does not break, does not crumble into fragments when damaged, does not harm the eyes, is cheaper than glass. Disadvantages: transmits UV rays with a poor-quality blocking layer, easily scratches, requires a storage case, deformation at high temperatures is possible. For example, glasses that were forgotten in a car somewhere in the south during a fiesta are often deformed. Especially if they are not of high quality.
- Glass: does not transmit UV rays, does not deform. Disadvantages: they are more expensive than plastic, if damaged, they crumble into fragments and can damage the eyes, not suitable for athletes or drivers.
The most popular have always been lenses made of mineral glass, organic glass (transparent plastic) and their combinations (approx. – laminated glass).
With the advent of new technologies, other materials have appeared.
- CR-39 (note – Columbia Resin No. 39)… Organic glass comes from 1940. It is softer than glass and requires additional protection, it is easy to break.
- Polycarbonate (approx. – Lexan, Merlon)… Created in 1953, this “plastic metal” is lighter, more durable and safer than glass. Absorbs almost all UV rays and does not require additional lens treatment.
- Trivex… The material appeared in 2000. It is resistant to impacts, lightweight, reliable blocking of UV rays.
Sunglasses with UV filter – how to test your glasses for UV protection, and what degree of UV filter will protect your eyes?
The sun is known to be the main source of UV radiation.
Moreover, the wavelength of the rays is of particular importance.
- The range of this long wavelength radiation is about 400-315 nm… It reaches the ground and accounts for about 95% of the sunlight. UVA rays have maximum penetrating power: they are able to reach the reticular layer of the skin. When hitting the retina of the eye, not protected by glasses, these rays trigger the mechanism of its damage.
- Medium wavelength option with 315-280 nm range… A small part reaches the ground and accounts for about 5 percent of the solar flux.
- As for the range of short-wave radiation, it is 280-100 nm – and is almost completely “inhibited” by the earth’s ozone layer. These rays are the most dangerous for humans, but penetration into the depth of the skin is impossible due to their short wavelength.
Poor-quality coating on glasses threatens with retinal dystrophy, cataracts and other troubles.
Which filters should you choose?
- Markup UV400 indicates the ability of glasses to block the harmful effects of UVA and UVB rays with a length of 400 nm.
- Marking Blocks at least 80% UVB and 55% UVA speaks about protection from UVB rays by 80 percent and from UVA rays – by 55. Experts advise paying attention to models where the value of each indicator is above 50%.
- Marking Cosmetic (approx. – cosmetic filters) speaks of low protection – less than 50%. In the summer, such glasses are not recommended at all.
- Marking General… These filters are considered universal and provide 50-80% UV protection. True, such models are suitable only for urban conditions in mid-latitudes.
- High UV-protection… These specific filters block almost 100% of UV rays. These filters are used in models for outdoor activities on the water and in the snowy mountains.
Sunglasses with 100% sun protection just don’t exist. If the seller convinces you otherwise, look for another store, you are fooled.
The degree of shading of the lenses of sunglasses, or Filter Cat
According to the degree of darkness (approx. – Filter Cat), lenses are classified as follows:
- Cat 0… These lenses transmit light from the sun up to 100% and are not darkened. But at the same time they are able to protect the eyes from UV rays.
- Cat 1… The level of transmitted light is 80%. Low obscurity is good in case of variable cloudiness.
- With degree Cat 2 only 40 percent of the light comes in. Therefore, the lenses will be good for walking in a not too bright sun.
- But Cat 3, transmitting no more than 15% of the light, are effective in the mountains, at sea and in the tropics.
- Well, the most powerful filters – Cat 4blocking almost 100% of sunlight. These glasses are necessary only in extreme situations, and even driving a car in them is completely dangerous – and even GOST is prohibited.
What is the difference between these filters (dimming) and UV filters? The former are needed for comfort while walking, and the latter are needed to protect the eyes from harmful sun rays.
Does the color of sunglasses affect eye health and vision, which color to choose?
When choosing the color of lenses (and today there are many fashionable colors), it is important to remember that the health of the eyes will directly depend on the color of the lenses. To avoid harm, ophthalmologists strongly recommend stopping at gray and green lenses… Gray lenses provide a more even distribution of light waves and a more realistic color image, while green and brown lenses reduce eye fatigue and strain.
Other lens colors:
- Red. It is forbidden to wear such glasses for more than 2 hours a day.
- Yellow. Extremely positive and bouncy lenses that turn even a cloudy day into a sunny day, enhance the contrast. Good for drivers.
- Blue. The color provides dilation of the pupils, and as a result – burns and damage to the lens. Strongly not recommended.
- Green… Indicated for people with glaucoma and intraocular pressure due to a decrease in the amount of intraocular fluid.
When choosing colored lenses, check if there is any distortion in the image when using them. The answer “Yes” is a reason to refuse glasses. The absence of distortion is a sign of the quality of the glasses.
Frame and vision – is there a connection?
In terms of eye health, the frame, oddly enough, also matters.
- Choose quality materials that are not allergenic.
- The strength of the frame matters.
- The stability of blood circulation and comfort of wearing depend on the convenience of the frame (the wrong frame causes headaches and fatigue).
The rest of the selection criteria depend only on a person’s taste, hair color and face shape.
Sunglasses with diopters – what to keep in mind when choosing?
Prescription glasses are worn by every third person, and in the summer, most of them have to suffer without eye protection from the sun. The best option is sunglasses with diopters that perform several functions at once.
The main options for prescription sunglasses are:
- Chameleons (approx. – photochromic)… Some of the most popular. These lenses have the ability to change color in accordance with the amount of incident light. Moreover, indoors, these lenses will be completely transparent, and on the street they are already getting darkened. Modern chameleons are also suitable for drivers.
- Tinted… For drivers and urban conditions, a degree of “tinting” of about 18-43% is suitable.
- Sun glasses… Such a mechanism, which allows you to remove or raise the sun protection pads, is not very convenient and is practically not used by manufacturers anymore.
- Polarizing. Eyeglasses recommended by optometrists with polarization offer such advantages as image clarity and absence of glare and optical noise, protection from eye fatigue and protection from UV rays, correct color reproduction and improved picture contrast. To check for the presence of polarization (even with the appropriate marking, it may simply not be there), you need to look at the LCD monitor with glasses at an angle of 90 degrees. The resulting image must certainly be dark in the presence of polarization.
Remember that sun glasses cannot be worn all the time! The addiction of the eyes to the lack of brightness of light affects the vision extremely negatively – an unhealthy reaction of the eyes to ordinary daylight begins, which threatens the development of photophobia.
The Bologny.ru website thanks you for your attention to the article – we hope it was useful to you. Please share your feedback and advice with our readers!
Must share this useful content with your loved one's
Visit Bologny for more useful and informative articles!