How to choose and wear sunglasses
How to choose and wear sunglasses
Sunglasses are also called sunshades. In summer and plateau areas, people often wear sunglasses to avoid the stimulation of strong light and block the damage of ultraviolet rays to the eyes. With the improvement of living standards, people care more and more about their eyes. In the sun, ultraviolet rays are more harmful to the eyes. About 7% of the sun's rays reaching the Earth's surface are ultraviolet. The cornea and lens of the human eye are the eye tissues that are vulnerable to UV damage. Cataract is an eye disease closely related to ultraviolet light. Solar keratitis, corneal endothelial injury, macular discoloration, retinitis and other eye diseases are all related to ultraviolet light. Qualified sunglasses have the function of blocking ultraviolet and infrared rays. Therefore, it can be said that wearing sunglasses in summer is one of the effective means to protect the eyes from ultraviolet damage.Sunglasses are generally divided into light and dark two categories, composed of a variety of colors. To judge the quality of sunglasses, the focus should be on examining several technical indicators such as top focus and prism degree, transmittance characteristics, surface quality and inherent defects, assembly accuracy and shaping requirements.
A pair of good quality sunglasses can play a role in shading and embellishing the appearance. But in the market, the reality is not optimistic. Some vendors are cynical, drill consumers do not know much about the quality of sunglasses, the use of poor material, cheap window glass or other inferior materials to make glasses. These materials have poor uniformity, contain impurities such as stripes and bubbles, can not block ultraviolet light, and do not meet the physiological requirements of the human eye. What is more, the use of visible light transmittance is very low, but the ultraviolet transmittance is very high quality plastic sheet to make sunglasses, causing harm to consumers.
How to choose and wear sunglasses? Experts remind consumers, do not only pay attention to the style of sunglasses, but also pay attention to its inherent quality. For qualified sunglasses, the transmittance of UVA with a wavelength between 315nm and 380nm shall not exceed 10%, and the transmittance of UVB with a wavelength between 280nm and 315nm shall be zero. Only by wearing these sunglasses can the cornea, crystals and retina of the eye be protected from UV damage. Some cheap sunglasses not only can not filter out the ultraviolet, but will block the visible light after the ultraviolet radiation is more significant, this kind of inferior sunglasses is not as good as not wearing.
Sunglasses belong to the flat lens series. According to national standards, sunglasses are only allowed with plus or minus 8 degrees of diopter, more than this error range is unqualified products. According to researchers' detection of sunglasses on the market, nearly 30% of sunglasses' diopter exceeds tolerance, and some even reach more than 20 degrees. Experts pointed out that consumers with normal vision wear these sunglasses, as if wearing a pair of myopia or farsightedness goggles, after a summer, consumers will be inferior sunglasses "training" into nearsighted or farsighted patients. When you have symptoms such as dizziness, nausea, and blinding after wearing sunglasses, you should stop wearing them immediately. https://readsunoptical.en.alibaba.com/?spm=a2700.7756200.0.0.6ee171d2jdbdBu
A pair of good quality sunglasses can play a role in shading and embellishing the appearance. But in the market, the reality is not optimistic. Some vendors are cynical, drill consumers do not know much about the quality of sunglasses, the use of poor material, cheap window glass or other inferior materials to make glasses. These materials have poor uniformity, contain impurities such as stripes and bubbles, can not block ultraviolet light, and do not meet the physiological requirements of the human eye. What is more, the use of visible light transmittance is very low, but the ultraviolet transmittance is very high quality plastic sheet to make sunglasses, causing harm to consumers.
How to choose and wear sunglasses? Experts remind consumers, do not only pay attention to the style of sunglasses, but also pay attention to its inherent quality. For qualified sunglasses, the transmittance of UVA with a wavelength between 315nm and 380nm shall not exceed 10%, and the transmittance of UVB with a wavelength between 280nm and 315nm shall be zero. Only by wearing these sunglasses can the cornea, crystals and retina of the eye be protected from UV damage. Some cheap sunglasses not only can not filter out the ultraviolet, but will block the visible light after the ultraviolet radiation is more significant, this kind of inferior sunglasses is not as good as not wearing.
Sunglasses belong to the flat lens series. According to national standards, sunglasses are only allowed with plus or minus 8 degrees of diopter, more than this error range is unqualified products. According to researchers' detection of sunglasses on the market, nearly 30% of sunglasses' diopter exceeds tolerance, and some even reach more than 20 degrees. Experts pointed out that consumers with normal vision wear these sunglasses, as if wearing a pair of myopia or farsightedness goggles, after a summer, consumers will be inferior sunglasses "training" into nearsighted or farsighted patients. When you have symptoms such as dizziness, nausea, and blinding after wearing sunglasses, you should stop wearing them immediately. https://readsunoptical.en.alibaba.com/?spm=a2700.7756200.0.0.6ee171d2jdbdBu
