Wolf,
Long time lurker, have never posted to any internet forum before but felt that perhaps I could help wiith some personal experience.
About 1 1/2 years ago I lost my right eye to diabetic surgery that became infected and was mishandled by the doctors. Long story short lost my entire eye and now wear a prostetic eye. Currently 54 years old.
Like you pretty bummed thinking perhaps shooting days were over. Just decided that I was going to overcome this "challenge" and enjoy shooting not knowing if I would ever hit the target again or not,
Started shooting with my old Rem pump .22. Felt very akward the first time I held the gun to my left shoulder and tried to pull trigger with my left finger. But with practice comes familiarity and after awhile it no longer felt strange, and I was starting to actually hit the target. I was ready to graduate to a centerfire caliber but didn't feel ready for .308. 30-06, etc. .223 sounded just right and I had always wanted an ar but had never gotten one. So after doing my homework and making sure that the brass would not smack me in the face I purchased a standard right hand DPMS 20" a4. Excellent rifle, love it. Actually when looking at it in the store the first time I shouldered it without thinking and thru force of habit I put it up to my right shoulder. Wow nice sights I said to the sales guy. LOL!!!
Again first time at the range it felt akward to shoot the ar left handed. I don't think it will ever feel as natural to shoulder any gun as it did when shooting right handed, just the way it goes. I don't ever notice the brass coming out in front of my face. The gun ejects the brass at about 4 o'clock and I have never been hit once.
My wife, God bless her, (she certainly deserves it after going thru the pain and 5 surgeries always by my side) felt bad for me and also allowed me to purchase my first semi auto shotgun recently. Again the Mossy ejects the shells out at 3 o'clock and again I don't even notice. One thing though the length of pull seems longer when I shoot left handed as opposed to right hand. I have noticed this with all of the long guns.
As far as shooting hand guns I still shoot right handed like I always did just now use my left eye. This works for me quite well. With alot of practice I am starting to get ok again. Actually just in the last week or so it seems like it is coming together. But alot of practice went in to it.
I still don't handle the recoil as well as I did right handed. The shotgun beat me up alittle the first time but again I think with practice I will adjust.
I once watched a video of a guy playing guitar with his feet because he had no arms or hands. God gives us alot of talent and ability that we don't even realize we have. Sometimes we just need the circumstance to come along that makes us "dust off" those abilities and put them to use.
Hope this helps.