Hi,
I'm having the same issue too. Tried going to Apple back in October after dropping my phone from only about a few feet only to discover the camera lens cracked! They wanted to replace the entire phone because it is considered accidental damage. They wanted over $300.
Previously, I had the iPhone 6 which had been dropped plenty of times over the course of 2 years with no signs of camera lens damage. This has to be a design flaw. My local repair shop will not fix the phone due to potentially compromising the water resistance.
So what options do I have here? Should I pay the $300 and get it fixed? Or try a couple different Apple stores and hope some will replace it at no cost? Is it too late into the warranty? I don't have AppleCare+.