paralax question
 

i have a leupold varixIII 2.5-8 . when in a fixed rest, if i move eye around the eye piece the cross hairs move around on a target at 25yds. how much is normal?? power is set a 4. it moves very little if any at 100yds. should i be concerned? i've always thought that your eye position didn't matter that much. thanks don