most scope manufacturers suggest you adjust the focus on the eyepiece to your eyes after mounting.it is important how far you are looking while you are adjusting the eyepiece.most shooters will look at a target at 50-100 yards to adjust the focus.however,they also recommend you set the scope to its highest power to sight in.sighting in at 100 yds are less sometimes will be a little fuzzy but will be clear at 50 on low power and maybe a little fuzzy at 100 then clear above 100 on highest power.it all depends on the quality of the scope,focus,your eyesight,amount of daylight, etc.i set my focus to my eyesight for 50 yards,turn to highest power and sight in at 50 for 3/4" high then shoot at 100 for 2" high.i am no expert but trial and error has been my mainstay for i have had the same problems myself.good shooting!