During an epidemic, many people wear masks in order to provide good personal protection. Many people think that they don’t need to apply sunscreen while wearing a mask, but in fact, they don’t. The main cause of photoaging is UV rays, which are everywhere, and ordinary medical surgical masks, which do not block UV rays. Special masks with UV markings for sun protection can achieve the effect of blocking UV rays, but for the exposed forehead and eyes, they cannot play the effect of sun protection. Therefore, if you need to go out for a long time, while wearing a mask, you should also apply sunscreen in advance so as to better protect your skin.