six times magnification should easily get you to 100 yds (and beyond)... if you are having difficulty, it's probably not your eyes (or age) - but more likely low quality optic.
There are lots of threads on this forum (and throughout the internet) with detailed info/reviews... you might want to determine spending limit and go from there (it doesn't have to be a lot - but of course cost is relative).
But to address you question directly - no, a magnifier isn't the answer... in fact magnifying a magnified optic will most likely further distort.
The root of evil - is trying to force others to believe what you think they don't understand. Just stop, and let true work. STOP. Don't question, don't qualify - just STOP. Let true work (it doesn't require you).