Hi, welcome to CT. The mint were handpunching the mintmarks into the dies until 1990. As a result slight alignments were normal.
Mint marks were hand punched on the die through 1989. This is not uncommon. Some times this was noticed and the mint mark was punched again which resulted in a repunched mint mark (RPM)
Try to take your photos like these. Here are the RPM's for 85D. http://varietyvista.com/02b LC RPMs Vol 2/RPMs 1985D.htm