It is going to be a hot summer day soon, and the majority of beauty loving women start to pay attention to their skin sun protection again. In fact, the correct concept is that sun protection should be paid attention to all year round in order to delay the aging of the skin and reduce the occurrence of skin tumors. Proper sun exposure is very helpful in keeping the body healthy, but excessive sun exposure can form discoloration, wrinkles, and loose skin, yet these are only what we can see with our naked eyes. In fact, it also causes a certain degree of damage to cells and genes, some cells are killed on the spot, while some injured cells release a chemical called free radicals, which stimulates capillaries and causes them to break down, which is what we usually mean by sunburn. In particular, UVA can penetrate the skin and damage cellular DNA, causing the skin to lose elasticity and, in serious cases, skin cancer. Timely sun protection has at least three benefits for the skin: anti-wrinkle, anti-spot generation, and skin cancer prevention. UVA: wavelength 320 to 400nm, the strongest penetrating force, can penetrate the clouds and atmosphere, directly to the ground, penetrating the dermis to cause skin redness and sunburn, UVA rays will seriously damage the dermis UVA rays can severely damage the collagen fibers of the dermis, causing skin dehydration, aging and loss of elasticity, and can cause permanent damage in serious cases. UVA rays are most likely to be encountered in daily life, so it is also known as “life UV”. UVB: With a wavelength of 280 to 320 nm, it can invade the epidermis of the skin and is the culprit of skin inflammation, dryness and peeling, causing sunburn and direct stimulation of melanin cells, resulting in sun spots and skin cancer. The most damaging time is from 10:00 a.m. to 2:00 p.m. UVB rays are strongest in places with strong sunlight refraction such as seaside and grass, so UVB is also called “leisure UV”. However, in recent years, due to the destruction of the ozone layer, it is expected that the damage of UVC to the skin will become greater and greater. Buy sunscreen products to know the relevant terms PA: PA is the abbreviation of protection grade of UVA, for the ability to protect A light, plus “+” as the definition of protection ability, up to three levels, PA + means light coverage, PA + + + means moderate coverage, PA + + + means high coverage. The U.S. system products with UVA protection function are identified by Broad spectrum on the product. PPD is the abbreviation of prolonged pigment darkening, which is also the ability to protect against UVA, commonly found in European products, and is divided into 1-8 levels. PA+ is equivalent to PPD 1-3rPA++ is equivalent to PPD 4-5rPA+++ is equivalent to PPD 6-8. SPF: SPF is the abbreviation of sun protection factor, a pointer to the sun protection function, representing the sunscreen in the UVB irradiation, protection against UVB light to protect the skin from sun redness and sunburn time. (Calculation: If the original 5 minutes will be red, the use of SPF15 sunscreen, can make the skin be red 15 times longer, equal to 75 minutes) How to choose a sunscreen Sunscreens on the market can be broadly divided into two categories: chemical and physical. Chemical sunscreens absorb UV rays and delay sunburn; physical sunscreens form a reflective film on the surface of the skin to isolate UV rays from invading. Generally speaking, chemical sunscreens are more refreshing, but more likely to be allergic; physical sunscreens are mild, but have a thicker texture due to larger molecules. In the purchase of sunscreens, be sure to choose the right sunscreen for your skin type. The actual skin is thin and has a lack of oil and water on the surface; the skin is flaky and rough in the fall and winter, and the skin feels taut and prone to fine wrinkles without applying moisturizer after the net. The surface of the skin of mixed skin type is easy to dry and easy to oil part, you can pick “part of the chemical + part of the physical” mixture of sunscreen, the best effect, and the texture of the product is also very mild, comfortable, breathable. The surface of oily skin is rough and greasy, the sebaceous glands secrete too much function, the skin texture is thick and hard, the texture is coarse, the pores are large, no transparency; the pores are easily blocked, forming acne, blackheads. The summer heat, easy to sweat oil, the most afraid of sunscreen is too thick, heavy, that will be more clogged pores, acne, so suitable to choose “chemical” sunscreen products. Oily skin people should choose water-based sunscreen, after wiping the skin surface is more shiny. The daily sunscreen principles and sunscreen should pay attention to several issues in daily life to develop some sunscreen good habits. For example, regardless of summer and winter cloudy or sunny, always apply sunscreen before going out. In the hot summer, avoid going out between 10 a.m. and 3 p.m. When possible, wear a hat, umbrella, sunglasses, long-sleeved shirt and long pants, and make full use of the shade of indoor passages, trees and buildings to shield your skin from the sun. Water absorbs ultraviolet rays, so you need to dry your body immediately after swimming to avoid tanning. Eating a diet high in protein and vitamin B can improve resistance to the sun. Vitamin C can repair the skin after sunburn and also prevent the production of melanin and dark spots. When it comes to sun protection, many people think it’s all about protection from the sun. In fact, there are many places in life that need sun protection, such as working in front of a computer for a long time, you need to do some protective measures for your facial skin. The sun’s ultraviolet rays are present even in foggy, cloudy and cloudy weather, so it is important to pay attention to sun protection at all times. Even in seasons other than summer, UV rays can take away skin moisture and damage skin tissue, so sun protection is a year-round task. Some people think that the higher the sun protection index of sunscreen products, the more effective the sun protection can be. This is a wrong understanding, the sunscreen index is too high sunscreen supplies easy to block pores, not conducive to perspiration, so rub on will feel uncomfortable, the correct choice is, in different occasions, for different requirements, the use of different sunscreen index supplies. UVA and UVB can damage the skin, so choose both UVA and UVB sunscreen is the best sunscreen. In addition, the number of times to rub sunscreen is not just once a day is enough, which should be treated on a case-by-case basis, the general degree of sunscreen sweat-proof for 30 minutes, the degree of waterproof for 80 minutes, such as a long time in the sun, you should repeatedly rub sunscreen, it is best to rub once every 1 hour.