Why sunscreen is important to human to cover up the face from the protection of UVA/UVB rays and mobile 📱 and computer 🖥 screens? 1) Is it mandatory to apply the sunscreen whole day from 10 am to 5pm 2)what happens if we don't apply sunscreen even in indoor and outdoor? 3) applying sunscreen even in indoor and outdoor is must? What are the complications if we don't use sunscreen for pigmented and seborrheic melanosis skin or else normal skin ? 4) Even we have Normal skin we should apply sunscreen? Please clarify sir/madam