Ahhh data ,that is what we're talking about here. People who have an eye dominancy problem who would like to try shooting with both eyes open. If your left eye dominant and you shoot right handed , if your dominancy is as bad as mine , you'll need a good 10" sight extension bar to bring the sight out to the left (on a right handed bow) , if you can see through the peep to begin with.
Not all eyes operate the same! I'll guarantee you that I could give you my lookers and you'd get very frustrated trying to shoot a right handed bow with both eyes open!

To say "DO NOT CLOSE YOUR EYES ,either eye" to someone with a strong single eye dominancy problem is ridiculous.

As for judging yardage? Doesn't effect me one bit! Most people judge yardage before even drawing their bow. And if the deer takes a sudden turn and changes the yardage? Simple...I open my other eye and watch until he stops.