Sun protection is getting more and more attention, not just in summer, when the sun is fierce, and not just outdoor activities, travel only need, sun protection is a year-round must do a homework. For skin care, sunscreen is arguably the most basic step, after doing may not be immediately effective, but if you are a little slow, it can quickly give you some “color” to see. So, sun protection is not only summer, not only outdoor, indoor sun protection must not be omitted, especially the seat at the window workers. A. Teach you to recognize the UV rays. UV can cause skin disease is mainly ultraviolet (UV) and visible light. UV is divided into short-wave UV, medium-wave UV and long-wave UV depending on the wavelength, of which medium-wave, long-wave UV is the main role in causing photosensitive skin disease spectrum. UVB can only reach the basal layer of the epidermis and can cause epidermal necrosis and hyperpigmentation with intense exposure. For example, if you go to the beach and come back, you can immediately see that your skin is red and peeling, which is UVB. On days when you go to work, you feel that most of the time you are not outdoors, and many people feel that there is no strong UVB indoors and there is no possibility of sunburn on the skin. However, there are still UV rays and visible light indoors, and the UV rays that can pass through the glass windows are “long wave UV”, which is the “UVA” on our sunscreen. UVA rays in the ultraviolet ray has a very strong penetrating ability, regardless of cloudy or sunny, as long as there are glass windows, it can easily penetrate into the room. Long-wave ultraviolet radiation can penetrate the epidermis to act on the superficial dermis, so that the skin tanning, and lead to lipid and collagen damage, resulting in skin photoaging and even skin cancer, the effect is slow and long-lasting, cumulative, not blocked by glass, umbrellas, clothing, etc.. Zhou Xian Coix said that the skin “photoaging” and natural aging is different, it will accumulate over time to make the skin rougher, resulting in skin aging, sagging, is irreversible, belongs to the skin “invisible killer. From 6:00 am onwards, the power of ultraviolet light is strengthening, usually the sun in normal life is very easy to harm the skin. If you are a white-collar worker who works from 9 to 5, the sunlight you receive is not very strong, or although you work indoors, but the room is well lit, it is necessary to prevent the damage of “long-wave UV”. This shows that indoors you still need to do your homework on sun protection, apply a nourishing isolation cream that suits you with sun protection, and try to avoid prolonged sunlight exposure to the skin. Second, how to see the sun protection factor? Many people use all kinds of different sunscreens, but they really don’t know much about some of the factors indicated above. Generally speaking, the SPF is a test index that measures the sunscreen’s ability to defend against UVB rays in the sun. The PA is the index that measures the sunscreen’s defense ability against the sun’s ultraviolet UVA rays. Currently, Japanese sunscreen products use the following three types of markings: PA+ (effective), PA++ (quite effective), PA+++ (very effective). There is currently no international certification standard for PA values. The value of SPF applies to everyone and is calculated by assuming that the intensity of UV rays does not change over time. A person without any sun protection measures will have red skin if he stays in the sun for 20 minutes, and when he uses SPF 15 sunscreens, it means that it can be extended by 15 times, which means that the skin will be red only after 300 minutes. Many people always think that the higher the sun protection factor the better when buying sunscreens, although it is said that the higher the SPF value, the longer the sun protection time. But high factor products often contain a large number of physical or chemical sunscreen, the corresponding stimulation of the skin is also larger, easy to block pores, and even breeding acne and pimples. Zhou Xianxi explained that in fact, the sun protection factor is only a reference number, in fact, it must also be considered in accordance with the individual’s skin quality, sunlight reaction, activity conditions and sweating conditions. Third, experts teach you the correct sunscreen. The actual sunscreen factor is only a reference number, but in fact it must be considered in accordance with the individual’s skin type, sun reaction, activity condition and sweat condition. The correct concept of sun protection because the isolation component must penetrate the surface layer of the keratin to play a long time to absorb the isolation effect, so it is best to wipe sunscreen 30 minutes before going out in advance. The dosage used is usually 2 mg per square centimeter on the skin to achieve the proper sunscreen effect. Some people think that sunscreens are more effective when applied several times, but the SPF value cannot be cumulative, and applying two layers of sunscreen will only have one layer of protection. The correct approach is, whether indoors or outdoors, sun protection measures are not just to increase the sun protection factor, but with sweat and wipe the loss of timely replenishment of sunscreen products. For sensitive skin, the choice of sunscreen products should be more careful, before using a new product, it is best to first in the back of the hand or arm or the root of the ear to try to apply, until 24 hours after no allergic reaction can be used. In addition, for people with eczema, blisters, and severe acne, physical coverage, such as hats and umbrellas, should be the mainstay. If you want to use sunscreens, it is best to use them under the guidance of a doctor to avoid aggravating the condition.