Sunglass is a kind of to prevent sunlight intense stimulation to the human eye damage eyesight health supplies, with the improvement of people's material and cultural standard, sunglasses and can be used as beauty or special jewelry that reflects individual style more.
Sunglasses can generally be divided into according to the use shading mirror, light color sunglasses and three types of special-purpose sunglasses.
The so-called sunshade glasses, just as its name implies is used for shading, people usually take in the sun by adjusting the pupil size to adjust the luminous flux, when more than the human eye light intensity adjustment ability, will cause harm to the human eye.
So in the outdoor activity places, especially in the summer, many people are shading mirror is used to keep out sunshine, to relieve his eyes to adjust the damage caused by fatigue or strong light stimulation.
Light color sunglasses not resistance to sunlight as shading mirror, but its rich colors and is suitable for use with all kinds of dress collocation, have very strong adornment effect.
Light-colored sunglasses because of its rich colors, style diversity, favored by the young gens, it is a favourite with fashionable woman.
Special-purpose sunglasses has a strong function of keep out sunshine, often used in the beach, skiing, mountain climbing and so on the energy of sunlight is strong in the wild, the ultraviolet resistant performance indicators have higher requirement.
Different people, according to the different preferences and different use to select the sunglasses, but from the most fundamental is to ensure the safety of the wearer and vision of the basic principles of damage.
Reduce glare, clear vision and deformation, prevent ultraviolet, no distortion of color identification, accurate identification of the traffic signal, should be the basic function of sunglasses.
If the function is flawed, does not light up the effect of sunglasses, it will produce consciously don't adapt to the symptom such as dizziness, eye acid bilges, argue sometimes slow to respond, color illusion and depending on the walk of unequal symptoms and cause traffic accidents, etc.
So choose sunglasses can not only focus on style while ignoring its inherent quality.
Consumers in the choose and buy sunglasses when it is important to note the following: 1, the first thing to know your choose and buy sunglasses from above, the purpose of the introduction of several categories of sunglasses, we know that different types of sunglasses have their different application occasions and the crowd.
We want a choose and buy sunglasses must first determine whether your choose and buy is for sunshade, or for the purpose of clothing decorative?
Besides the shade have uv resistant requirements?
The safety of the lenses properties have special requirements?
Only clear the purpose, combining the practical effects of the design and put on my face to buy a pair of appropriate sunglasses.
2, learn to understand product label is not all sunglasses have the function of anti ultraviolet, meet the basic requirements of the standard sunglasses, can only say that while blocking light not through more ultraviolet light.
If only a pair of sunglasses to block light, but not cut off with the same amount of uv light, for the wearer will receive more than don't wear sunglasses ultraviolet (
Passes into the eye wear sunglasses, will reduce the luminous flux, the wearer pupil enlargement)
On the shop counter sales of sunglasses, the lenses, tag or on the packaging usually have obvious signs, as the fabric composition on clothing label, when consumer is bought be sure to check carefully.
About ultraviolet prevention function identifies a pair of sunglasses ultraviolet prevention function, we can't identify with the naked eye, the manufacturer of the product is an express promise consumer choose and buy has the protective function of sunglasses only reference, we can see in some of the product label and glasses positive such as: '100% of ultraviolet prevention', 'UV400', 'cut off all of the ultraviolet ray', such as 'anti ultraviolet' express identity.
Ultraviolet (uv) refers to between 200 nm to 380 nm wavelength of the sun's rays, including three categories: UVA wavelength of 315 nm to 380 nm, UVB rays wavelength of 280 nm to 315 nm, UVC wavelength of 200 nm to 280 nm.
The sun's rays reaching the earth's surface (
In the ultraviolet (uv) accounted for about 13%, and more than 97% UVA, UVB accounted for 3%, UVC close to zero.
Ultraviolet radiation to the human eye injuries mainly depends on the wavelength of ultraviolet light, radiation time and radiation intensity, the strength of the defense mechanism, the human eye and cornea, lens uv damage are the most common eye tissues, sunlight keratitis and corneal endothelial injury, daylight cataract is the most related eye diseases.
In order to protect the health of the eye, can choose which has the function of anti ultraviolet lens sunglasses, try to eliminate under 380 nm uv light.
Logo on safety performance sunglasses with safety performance, the lens using impact resistant materials, such as PC tablet on the label and manual tend to be marked 'shock resistance' and 'through the FDA certification', 'conforms to the highest standards in Europe and America and so on, if the product can meet the requirements of logo on, motorcyclists, drivers, etc have special request for the safety of consumers is a good choice.
Commitment to the product identification, consumers should learn to protect themselves, keep the label or instructions or good, or let the merchants marked on the invoice, in the event of dispute, we would not be a lack of evidence and passive.
3, to identify the lens inner quality of basic skills (1)
Degree of the lens should meet the requirements of the flat lens, and should not have affect vision optical spot disease.
Simple identification method for, can put sunglasses in sight, observations of distant places through the lens, such as window frame or door frame, then glasses from top to bottom and move around, goals should not have swings and wavy deformation.
The color of the lens can not partial, should make the distortion of the color of the surrounding environment, the edge of the object clearly have the ability to effectively identify the different color lights.
Lens color shades of choose, because of depending on the required activities, according to different light sources and occasions, the color of the lens will affect the shading effect.
To make the sunglasses can effectively block the summer light, the color of the glasses with enough depth, but by bike or drivers, don't choose the lens color is too deep.
Sunglasses wearing inappropriate susceptible to eye disease, cloudy and there is no need to wear sunglasses indoors.
Some people all occasions, regardless of sunlight intensity, even during the evening and in the evening, also wearing sunglasses when watching a movie, TV, it will inevitably increase burden of eye accommodation, cause eye muscle tension and fatigue, make the vision loss, blurred vision, serious can appear the symptom such as dizziness, not long.