Eye orientation question

Hi
I have been told by a very knowledgeable shooter that the more bladed you  stand the muscles in your shoulder are stronger, thereby easier to hold the gun up, steady. Due to physical limitations the best I can do is maybe 50 degrees to the target, and that leaves me looking out the very corner of my eye. I have been shooting this way and it seems to work. 
In shot gun sports it is always taught head level eyes straight foward, is it the same for bullseye? 
In other words does it matter if I look out of the corner of my eye or is that a disadvantage ?
Thank you, Tom

May cause issue with toric (for astigmatism) contact lenses, rotating them. Looking strait forward I don't get a sunburst on my dot but fully bladed sometimes I have to keep blinking until the contacts get rotated correctly.

Ideally your eye should be near the center. Looking out the side will be more fatiguing. I don't think there is a universally ideal angle to raise the arm, but going to extremes is usually not the right answer. I agree the big muscles of the shoulder are oriented to be strongest raising the arm out to the side, but we are only lifting about 2 lbs. Most people should have the strength to hold the gun up at any reasonable angle.

If you have a physical limitation the prevents you from turning your head or holding the gun at a particular angle, then you have to find the best compromise and learn to use it to the best of your ability. FWIW I think stance is one of the least important "fundamentals". I can rotate my body facing the target or turning all the way to the side and it doesn't change my scores significantly. Most of bullseye success is in the mind and the trigger finger.

Stretching and Yoga might help you turn you head more so you don't have to look out the side of your eye. (don't take this as medical advice). I find if I skip stretching for a while my neck gets tight and I can't turn my head as far to the side.

Strengthen the arm with a 2-3 pound dumbell, hold it up for 20-30 seconds, then rest 20-30 seconds (or alternate arms). Go for more reps rather than more weight. If you want to build a position more square to the target, raise the weight at that angle. To reduce boredom I do variations... raising and holding, drawing small slow figure-eights with the hand while holding, raise both arms with weights, bring them slowly together in front, then open both arms out to the sides, then lower etc. I've heard of some people doing this in the car while driving, but for me is uses different muscles when I am sitting.