Unfortunately, most of us don't wear sunscreen, and those of us who do can't really tell when it wears off, because it's invisible.
لسوء الحظ معظمنا لا يضع واقي الشمس، والذين يضعوه مِنّا لا يمكنهم معرفة متى يزول، لأنه غير مرئي.