How to pick up sunglasses
Sunglasses can be called one of the main summer accessories. Few people think about how well sunglasses fulfill their purpose – protection. For most, they are a fashionable ornament that allows to emphasize the style. But from the name it is clear that sunglasses should protect us from the sun, or rather from the harmful ultraviolet radiation.
Even in small doses, ultraviolet light will not be useful for the eyes – it has a negative effect on them. Long stay under the scorching sun without protection can lead to temporary loss of vision, corneal burn and cataract. Even a cloudy day should not be a reason for the rejection of glasses, because the clouds are not able to block the UV radiation and many rays penetrate through them that can damage the eyes. Another reason for the constant wearing of glasses – the ability of ultraviolet accumulate. This becomes one of the causes of vision deterioration with age.
Sunglasses lens protection
Dark lenses of glasses are not always a guarantee of protection against ultraviolet radiation, since the degree of shading does not affect the level of protection. This is ensured by special films on the surface or in the body of the lens. Most cheap and low-quality products miss almost 100% of UV rays. The choice of sunglasses should be based on their quality and degree of protection. Information about it should be contained in the certificate attached to the glasses, but it may be present on the label. Often they indicate the degree of protection from two types of UV waves: medium-length waves belonging to category B, and long waves belonging to category A. Both those and others are equally dangerous to the eyes. The inscription is as follows: “Blocks at least 70% UVB and 45% UVA.” Information means that they detain 70% of category B rays and 45% of category A rays. The higher the performance, the better the lenses protect the eyes.
Degree of lens protection
For a city, sun glasses are ideal, retaining 50% percent of ultraviolet waves. Glasses with a high degree of protection should be worn near the water and in the highlands, in some models it can even reach 100%.
There are plastic and glass lenses for glasses. Each of the materials has its pros and cons:
Glass lenses. The advantage of glass lenses is the ability to trap ultraviolet light. Even clear glass glasses provide eye protection. Unlike plastic, they do not distort the image and are less prone to the formation of scratches. But they are more fragile and heavy.
Plastic lenses. Plastic is a durable and lightweight modern alternative to glass. High-quality polymeric materials can exceed the characteristics of glass, so most manufacturers prefer it. Regular plastic does not protect against UV light: wearing it can lead to eye problems. So that he does not miss the harmful rays, coatings are added to it.
High-quality sunglasses with color lenses should keep all colors natural and only slightly change their shade. If they radically change the colors of the world around you – it is a fake.
Colored glasses, especially bright shades, such as pink or red, are harmful to constant wear. They cause eye fatigue, disrupt perception, and affect mental and physical condition. The optimal color for lenses are brown and gray tones. They are suitable for medium and bright sun, provide optimal contrast and good visualization.
Color lenses points
Behind dark green lenses eyes will be comfortable – they reduce their fatigue. Glasses with yellow lenses will be the choice for athletes. They provide excellent contrast and depth of visibility, even in dim lighting. Mirrored sunglasses reflect glare and do not tire the eyes.
The best material for the rim is nylon. It bends, but does not deform. Frames made of plastic are fragile and can quickly become unusable. Metal and titanium frames have proven themselves well – they are not bulky, strong and durable.
Sunglasses Selection Guidelines
Try to buy glasses that are suitable in size, only in them you can feel comfortable. They will not squeeze the nose, squeeze behind the ears or move down the nose.
Choosing a frame, it is recommended to be guided by some features of the face. She should not close eyebrows. Bad will look like glasses, repeating the shape of the face. For example, round or rounded frames are contraindicated for chubby – the more rectangular ones. People with large facial features are encouraged to abandon thin metal frames. Dark glasses with a low jumper will reduce a large nose.