What if the lens in front of the camera lens is loose?

There are several cases of fuzziness, 1. The lens in front of the lens is covered with dust after long-term use, so you can scrub the lens with alcohol. 2. The lens part of the camera is loose, resulting in inaccurate focusing. It's vague. Turn on the camera and twist the lens to see if it is loose. 3. The lens part of the camera is broken, which leads to blurring. Replace the lens part of the camera. 4. The camera is aging for a long time, resulting in blurring. Replace the camera.