Most of the smartphones lens is located outside of the body. Touching the lens with naked fingers can affect the lens of camera.So Inorder to clean it take a microfiber cloth and Fold like a triangle so you have a sharp corner and then clean the lens .
Use a small blower brush to remove dust and debris from the lens. Do not blow on the lens with your mouth. It increases risk of accidentally spraying the lens with saliva, as there are acids in our breath that can actually damage the lens coating.
If their is Dirt inside remove the back cover of your phone and use small amount of alcohol-based liquid lens cleaner and a Q-Tip cotton swab to clean lens from inside the back cover. Its a bit risky. Until its done don’t let liquids get inside your lens.
