No offense intended, but I find it next to impossible to do that!.....Then again I shoot hand guns with my dominant eye(left)(right handed grip on gun) and shoot rifle with my non-dominant eye(right)(right handed grip of course).....I just can't handle a rifle as well left handed so I am forced to use this method.....I always keep both eyes open(regardless of firearm) unless I am really trying to precision shoot something and don't want to see anything but the target....then I either fully or partially close the "off eye"
Ps Cross-eye dominance sux for left eye right handed rifle guys
But with nose to charging handle(ar) and a red dot co-witnessed to irons,
amazingly enough, my shooting without the dot has improved also
:edited to say: right handed pattern today at the range @50yds was 6-8inches/irons sights
and 3-4inches with red dot
remember this is with my bad eye
I hope I can out train this....