Sunscreen is indispensable throughout the year, and skincare is not perfect without sunscreen. Sunscreen works by shielding the skin from ultraviolet rays.
What people call “ultraviolet” can actually be subdivided into long-wavelength UVA, medium-wavelength UVB, and short-wavelength UVC.
UVA is UVA, UVB is UVB. Both of these waves can enter the skin and penetrate the dermis, causing the skin to tan. UVB is usually found outdoors and is stronger in summer or on sunny days. And UVA is no matter the four seasons sunny rain, indoor and outdoor are everywhere even if the winter you are in the overcast day of the outdoor station a day, although won’t feel the skin was suntanned, but the effect of UVA will slowly accumulate in your skin, stimulate pigment synthesis and make the color of skin black, which can cause skin aging and fine lines.