A missing finger in a dream often carries outsized weight for something so small -- a minor loss of capability that feels disproportionately significant, like a skill or precision you're worried about losing. It can point to vulnerability around a detail others might not notice but that you feel keenly.
Let the Moon be increasing in light, and free from the aspects of the infortunes, when you would cure sore eyes. - William Lilly (1602.-1681.)