Auto-dim rearview mirror problem

The area that darkens at night on my auto-dim rearview mirror has been slowly shrinking the past few months. I now have to adjust it at night to make sure headlights are shining on the right spot of the mirror. Does a product exist to address this issue (i.e. some type of coating) or will I have to replace it? Thanks.

I think you’re going to have to replace it. You might get lucky and find one in a salvage yard or at one of the websites that query salvage yards nation-wide (,, etc.)