How to choose the right sunscreen? First of all, we need to have a correct understanding of sunscreen products, and understand the sunscreen mechanism, so that we can choose the right sunscreen for our skin, and avoid the damage to our skin caused by blind selection of the wrong skin care products.
First, choose sunscreen that can isolate UVB and UVA at the same time and most effectively. Physical sunscreen can only block the UVB band, and the protective effect is weak, which can not effectively protect the skin from the penetration of UVA on the skin. Therefore, it is necessary for chemical sunscreen to absorb and convert the full band UV energy. At the same time, ultraviolet radiation will cause free radicals in the skin. Waterfall type extended damage requires bioactive substances that can resist ultraviolet radiation, such as vitamin E, to reduce the generation of free radicals, thus blocking, slowing down tissue damage and promoting post sun repair.
Secondly, choose sunscreen products with high SPF index. SPF index represents the isolation and protection ability of UVB radiation. In clinic, the measurement of SPF index needs to smear 2 mg dose on every square centimeter of skin, but in reality, the average dose is only 0.5 mg / square centimeter, which can not achieve the effect that the SPF index on the product logo can achieve. The sunscreen products with high SPF index, due to the higher efficiency of blocking UV, can properly make up for the defects caused by insufficient dosage.
Finally, choose products with high UVA protection index. PPD index is commonly used to measure UVA protection index in dermatology. The higher PPD index is, the better the protection effect is. The PA '+' selected in China is also an internationally recognized protection index for UVA. However, when PPD & Ge; 8 is PA + + +, it is the highest UVA protection index. It is suggested to pay attention to the specific PPD index when choosing sunscreen products.
In particular, dermatologists say that good sunscreen habits are the key to protecting the skin from damage.
The specific precautions are as follows:
1. Use appropriate sunscreen products throughout the year;
2. Do not expose to the sun directly between 11am and 4pm, especially in summer;
3. Even if you choose sunscreen with waterproof function, you still need to apply it repeatedly after swimming or sweating;
4. Avoid direct skin exposure in the sun. Wear T-shirts, sunglasses and hats;
5. In the sun, apply sunscreen every 2 hours;
6. When you are exposed to the sun for a long time, you should replenish a lot of water on time;
7. Children under the age of 3 should not be exposed to the sun too much.