I use no line in everything. It took a little while to get use to them. On shooting glasses I have the correction set lower. First set I was still using part of the progressive near correction part of the lens when I mounted the gun. Think about the rib being in focus near or far as a distraction. I want the end of the gun in decent focus and the bird in clear focus. Solution was to move the edge of the distance vision down several mm's. Now when I mount the gun I can see clearly now. I still miss but that is due to operator error.