Features of standard sunglasses + recognition method

Glasses should absorb at least 98% of UVA and UVB because the non-standard glasses are much more harmful than not wearing them because the sunglasses cause the pupil to open and now if it does not absorb UV, all harmful rays penetrate the eye.

Ultraviolet (UV) radiation has three types of UVA, UVB and UVC wavelengths that absorb “UVC” into the ozone layer and do not reach the ground, and the area that is harmful to the eyes is UVB, which can cause skin burns and harmful effects. On the eyes. Excessive exposure to UVB rays can lead to irreversible long-term illnesses, such as cataracts, changes in vision and pterygium. “UVA” radiation is mostly absorbed by the lens of the eye and there is no evidence of eye damage.

The use of sunglasses has been suggested as a necessity to maintain eye health. Protecting the eyes from the intense sunlight and UV radiation is important. Wearing good sunglasses when exposed to extreme sunlight improves vision and prevents damage to the lens and the retina. Wearing fake glasses not only doesn’t have this property, they can also cause many eye complications, including vision loss, cataracts and retinal disease.

Advice on choosing sunglasses

 People who are skiing, sunbathing and mountaineering at high altitude must wear sunglasses. For these environments, glasses need to pass only 8-12 percent of the light.

 Green and brown colored glasses are harmful because they disrupt the color spectrum. Of course, for those who want to drive for a long time, it is advisable to wear brown glasses because these glasses increase the blue light of the sky to reduce the unity of vision, so it is not recommended for everyday use.

If you sit behind the wheel, it is advisable not to wear green sunglasses as it may impair the detection of red and yellow light and are not appropriate in this regard. As a matter of fact know that the best color for sunglasses is gray first and then brown.

آ Sunglasses glass should be of sufficient strength. Polycarbonate is the most durable of all materials.

The glasses frame must be large enough to provide complete protection.

A standard sunglasses is a spectacle that when waved against a patterned page should not see a wavy, wavy screen.

If you want to know if your sunglasses are dark, look in the mirror in a room with ordinary sunglasses. If your sunglasses are right, you should not see your eyes.

 If you are exposed to too much radiation at your workplace, sunglasses will not work, so it is advisable to use special glasses (for example, welding or working with radiation-producing glasses or special protective equipment).

People who undergo laser cataract or excimer surgery. They should wear authorized sunglasses in the same way as other people.

 Some skin or ophthalmic drugs increase the sensitivity of the eyes to sunlight. When using these drugs (for example, those who use doxycycline eye drops or tablets), they must wear sunglasses.

Reflective sunglasses with mirrored glass are suitable for ski or mountaineering purposes.

 Given the various costs you incur daily, buying a standard sunglasses is not only the right thing to do, but also necessary. The value of using fake glasses is to endanger the health of your eyes

It is best to consult an ophthalmologist or get an optometrist for sunglasses. And go to reputable eyewear stores to buy it. You can easily use it for up to several years by buying a good spectacle.

If you have impaired vision and are wearing eyeglasses, you can use special sunglasses on your eyeglasses or order photo glasses or colored glasses for your eyeglasses.

How to recognize standard glasses

“In the lens of cheap glasses is a substance called Triace tate that absorbs only 40% of UV and is very harmful to the eyes, so the best way to know about standard glasses is to use a UV meter, which is often found in reputable eyewear stores.”

Without the use of a Uv meter to identify the standard of sunglasses, it would be difficult and even impossible for the ophthalmologists to identify a suitable sunglasses.

It should be noted that the device should show UV glasses from 98% above. Occasionally, the “400 UV” mark is also inserted alongside some glasses, indicating the ability to protect against UVB.

Not every expensive eyeglass can be considered standard and they all need to be tested with a Uv metr device.

Properties of non-score glass glasses

Most sunglasses are now considered glass because of their high cost, but it is interesting to know that if you put unnatural glass in front of your eyes, it will absorb up to 98% of UV. What is important in choosing sunglasses is that the whole eye should be taken with it, so it is not recommended to use small glasses that are more beautifully designed and have no cover.

Do children also need sunglasses?

Children need sunglasses because they may be exposed to more sun than others. The younger people are, the more UV will damage their eyes, because the cornea and lens of the child’s eyes are very transparent, and UV goes into the eye without returning it, while in older people because of the opacity of the lens and the cornea, it will reflect some UV. , So it is best not to forget children and adults in the sun from 9am to 8am, because during this time, even if the person is in the shade, the danger of UV radiation threatens the eyes.

Polarizing filter

Most harmful rays come from the equator and are horizontal. Polarized glasses can block these rays as they allow only vertical rays to enter the eye, and the only problem with these glasses is that if you have a car (LCD) you will have a little trouble looking at this page. This is a problem and you may not see this page clearly. Therefore, these types of glasses are highly recommended for people with very good vision and a job as a pilot or shooter.

Does the color of the glasses glass also matter?

The different colors and layers in the glass are tailored to suit each application, such as gray because they reduce the intensity of light in all colors uniformly and cause the least color disturbance, suitable for driving and other everyday applications. . In certain situations, colored glasses are more attractive, for example, for skiing as yellow glasses are more likely to absorb blue.

In addition to better absorption of blue light and high frequencies, brown glasses also absorb more UV, and green glasses filter out part of the blue light and reduce surface brightness, and eventually red and purple glasses that are more suitable for hunting and skiing. Suitable water is used in green and blue environments.

Do we also need sunglasses in winter?

Wearing sunglasses in winter, especially in snow, is recommended. Since snow reflects 80% of UV and the earth and water reflect only 10% of UV, the importance of wearing sunglasses in winter is no less important than in summer.

All kinds of sunglasses frames

1- Plastic

* CELLULOSE ACETATE – ZYL: Affordable and very lightweight.

* PROPIONATE: Nylon plastic that is non-allergenic and lightweight.

* NYLON – GLIDAMIDE: Glidamide is resistant to heat and cold and is not flexible but hard and allergenic. Plastic frames are more fragile than metal frames and withstand their strength as the sun shines.

– Metal

* MONEL: An alloy of several metals. It is anti-corrosion and usually has a palladium coating.

* TITANUM: Lightweight, durable, corrosion-resistant (silver color)

* BERYLLIUM: Cheap Price, Resistant to Corrosion and Blurring, Highly Flexible (Matte Gray)

* STAINLESS STEEL: Anti-sebic acid does not increase weight and allergens, it is resistant to corrosion and wear due to the presence of cremium metal in its composition.

* FLEXON: Titanium alloy type is known as “memory metal” because it returns to its original shape if damaged. Even after twisting, bending and crushing. It is not lightweight, anti-corrosive and allergic.

* ALUMINUM: Lightweight, highly resistant to corrosion, combined with iron and silicon for greater durability. The cream should be the same size and complement to the shape and color of your skin. For example, people are better off choosing rectangular frames, and people with square and rectangular faces are better off choosing oval frames. Another point is that the top of the frame should not cover your eyebrows.

Types of frames, lens …

Frame types

WRAP-AROUND: refers to frames that follow the face arch and cover the eyes completely. They are also protected against snow, wind and rain.

CLIP-ON: Frames referring directly to medical glasses.

Why are some lenses darker than others?

The amount of lens blur depends on the environment you want to use the eyeglasses. In high light environments such as mountaineering and snow skiing, you need a lens that blocks most light% 95% for driving and seafront absorbing% 70-90 light and lenses that absorb% 10-20 light. Reduces is just for the sake of fashion and good looks. The important thing is that the lens’s darkness has nothing to do with the amount of protection it has against UV. Lens colors and their application, lens coatings…

Lens color

Lenses are available in metaphorical rings, each suitable for special activities.

Gray-tint: A super-tint that reduces overall light brightness and protects the eyes from glare and is suitable for driving and general use.

Yellow and gold tint: Reduces the amount of blue light and allows other frequencies of light to pass through. Yellow tint generally eliminates blue tint and makes everything look sharper (because blue light tends to diffuse and reflection, so removing it is effective in clear vision) and that’s why most eyeglasses are special. Snow skiing are yellow. In fact, this color disturbs the visibility of the light and is also suitable for driving at night, cloudy and foggy weather.

 Brown and Amber: These are general colors and have the benefits of reducing the glare and eliminating high frequencies of light such as blue light and violet light. Like the color yellow, it disrupts the light’s vision but enhances the contrast and sharpness. Suitable for running, cycling and driving.

 Green Tint: Reducing the glare and blue light is one of the features because green tint provides the highest contrast and the highest degree of sharpness.

Pink and red tint: Provides excellent contrast with the blue and white background objects. Suitable for hunting and water skiing.

Blue – Most blue light passes through them. For golf and tennis, or pointing to green goals.

Lens coatings

Ultraviolet: This coating blocks ultraviolet radiation. Be sure to choose eyeglasses to remove 400 nm waves and block 100% of the violet transient waves when purchasing glasses. Some sunglasses also remove infrared rays.

 Scratch-resistant: Scratch resistant to plastics because the glass lenses themselves are almost scratch-resistant.

Photochromic: Photochromic lenses darken when exposed to sunlight. These lenses are made of silver chloride and silver halide coatings. Note that the photochromes do not react to visible light and only darken when exposed to ultraviolet radiation, so they do not pass through the UV of the car’s glass, so I do not use a photochemical lens. Be. Sometimes it takes up to 8 minutes when the lens needs to be darkened.

Flash or mirroring: These mirrors mirror the lens and reduce and absorb about 10 to 60 percent more light. It can be silver-gold or copper. Suitable for snow and water in the highlands.

Ar- or anti-reflective: A coating that has the same coefficient of contrast between the air and the angle of illumination and the intensity of the light illuminated from the inner and outer surface of the lens. In fact, this coating allows the light to reach the eyes while also reducing the glare and also making your eyes look darker. Very suitable for night driving.

 Polarization: Light waves and artificial light sources such as vibrating light bulbs are distributed throughout the body. In these experiments, materials were used to align each other in a parallel relation to each other. When light is applied to the lens, it acts as a microscope filter and absorbs light waves that correspond to parasitic rows and transmits the remainder of the lens. Most optical illuminators come from horizontal surfaces, so these lenses are adjusted to eliminate the waves of horizontal reflection and allow you to reach surfaces such as water, ice and snow.