This is also why I do not let others shoot my guns and adjust site. I had a friend in the guard who said I will adjust it for you cause it is shooting off alittle. I spent 10 minutes telling him that it was dead on for me and he needed to just aim off alittle and no to touch the scope. Of course with iron sites this can be a issue. This is why I have been shooting my glock with each eye and with both open.