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I've had this problem all my life ... I've never had the world's best eyes, always needed glasses and started wearing them in 4th grade. Yet, with diligent practice and paying attention, I've never had any problem manually focusing with either an SLR, an RF, or the new "mirrorless" (TTL-EV) cameras. I prefer focusing manually in most cases still, although I'll be the first to say that a good AF system is an amazing convenience when it works.
But that's what it is for me most of the time: a convenience. I've had only two cameras that AF proved essential with ... a Sony R1 and an Olympus 8080WZ. The manual focus capability of both those cameras was awful, for different reasons, and spot-AF-on-demand was the only way I could achieve critical focus consistently.
I'm 62 now. My eyesight isn't what it was 10, 20, or 50 years ago, regardless of how good or bad it was then. But I can still focus with confidence.
My current daily use cameras—Leica M and SL—are both easy to focus. The SL's excellent AF with the SL24-90 lens is convenient, fast, and accurate, but I still prefer manual with it most of the time. My less frequently used Hasselblad 500CM is more work to focus, and of course the SWC with ground glass back is similar to that, but I manage well with them too.
So ... Don't think just because your eyesight is getting a little less than it once was that the world is ending and you must use an AF camera. It just takes some attention, some practice, to develop the necessary skills again and keep them up. Don't be lazy ... work at it! 🙂
G