Yo
JohnnyH....don't feel bad, I'm older than you by a good few years. I'm sorry to hear your knees are 'gone' man. Knees are a bitch. Almost worse than back problems.....but still, both painful and debilitating as all get out.
My job has not been good regarding injuries. Broken back and neck...2 different injuries-4 major spine fusion surgeries 2007 to 2010, partially amputated my right thumb at the first joint, that they put back together, both big toes gnarled up by super heavy loads rolling over them.... impingement surgery on one shoulder.........etc etc.
Starting with the military, in the motorcycle industry for 25yrs and then in the last 21 yrs or more, in my current job in Film & Television production, totally extreme, brutal and downright dangerous at times. 10-12hr days every day, sometimes weekends too.. Also I've concurrently been a pro musician all my life-which is my main love in life...guitar. player. Sounds easy but lot's of heavy lifting there and awful posture issues I'm now trying to correct. Tough isn't it bro'? The young kids here have it all to look forward to.
Regarding eyesight: Big problem. Of course mine started going south at 50.......and progressively have worsened. Where I have a huge issue
JohnnyH is when I am training with real weapons. I have been a shooter for years going back to my military service with real SMG's, pistols etc and my fave rifle ever for all the wrong reasons....my service rifle, an FN FAL 7.62X51mm NATO-yeah baby!!


. Before that it was break barrel air rifles as a kid.....always been around firearms and pellet guns.
I go out as often as I can and train with my pistols of various calibers and/or my AR-15's, AR-10 and AK-47 MSR's.......Modern Sporting Rifles. I also shoot long distance marksmanship, which is my favorite rifle discipline by far..... with the .308, 5.56 and 6.5mm Creedmoor precision rifles. Precision shooting is where the eyesight/glasses thing gets serious.
Dude! My eyesight is
REALLY messing with me right now. I cannot find one prescription that works for everything.....contacts or glasses. I'd kill for 25 year old eyesight again. I'm even looking into eye surgery, where they replace the lens.
Hang in there man......the games are awesome for hand/eye co-ordination, keeping your brain sharp and just relaxing. I just regret not being able to play as much as I would like to, during the Coronavirus shutdown BS. Too many things to do at home and now I am also teaching my 19 and 14 yr old daughters to surf on the weekends as well.
Don't get couch locked man. We should all prevent becoming sedentary and gamers of all ages, shapes, sizes and level of physical condition....need to get some exercise....... in between campaigns of course.

Anything helps...walks, bike ride, situps, pushups and other body weight stuff, isometrics etc. It doesn't have to be extreme, in fact it is way best to start off super easy if one is not in shape......and just keep doing it until you feel you are not getting any more benefit ....... and then one can up things a bit. Small increments, baby steps.