As I have aged, and those open irons grew fuzzier , I found the best rifle sight to be a receiver, "peep" sight . Placed as near to the shooting eye as possible worked best. A Williams 5D Receiver Sight worked well on an older Winchester model 94 that I wasn't going to bulk up with a side mounted scope( that just wouldn't do) ). I haven't tried a fiber optic front yet, but it sounds like a good idea. Might be a big help picking it up.
What I like about peeps is you look through the aperture and only have to focus on the front sight and target.
I have found that peep sights mounted farther away from my shooting eye don't work as well. I have a MoJo sight mounted on a !911 Swiss Schmidt-Rubin but haven't made it to the range to actually test out the barrel mounted peep.
The peep sight I tried on a Ruger Blackhawk didn't work for me, too far away from my eye.
Gary