It’s the harmful amounts of ultraviolet rays that can damage the skin and are the very rays that tinted windows prevent effectively. Remember how you have to make sure that your skin is well-protected from the sun even as you bask under it to get tanned. The lotion will block ultraviolet rays from being absorbed by the skin and minimizes the possibility of skin cancer. This is the same logic as to why you put tint on your windows, a protection from the sun even when you’re indoors.