My brother has Stargart's disease ( a serious eye disease) , and needs a crossbow scope that has only one crosshair with NO other marks, lines, extra hairs. I have been unable to find any that will take the vibrations of a crossbow. I've contacted nine crossbow mfg's with no help. They all have multiple crosshairs or some other kind of ranging dots Tried some rifle scopes but eventually they all fell apart inside. Anyone have one ( my original Horton had one) laying around, or know of where we can get a single crosshair crossbow scope?