I suggest more practice. Make a clear and safe weapon, and then practice focussing on the front sight with both eyes open. Do this a lot, and with different targets at different ranges. Then try it on the range, first at close ranges until you're comfortable, and then move the targets back when you're ready.
I find I can shoot pretty well (nothing that will win an accuracy competition, but definitely well enough to drop a BG) with both eyes open, but only at very close range...Say 20 feet or so.
I haven't tried this with a rifle yet, but when I get a chance I'll post my findings.
Real men use iron sights.
"A fear of weapons is a sign of retarded sexual and emotional maturity." - Sigmund Freud, "General Introduction to Psychoanalysis."