I mean, of course exercise isn't going to fix your vision. But if your vision is going to degrade, you can still choose if you want to live as a fit and healthy person who needs reading glasses, or as a person who has aches all over, is in bad shape, feels tired and like shit all the time, and on top of all that needs reading glasses.
I feel like shit when I exercise, and on top of that it's extremely mind-numbing. On par with watching paint dry.
I am in my mid-40s, don't do regular exercise, and still dont feel like "shit".
Really, this "motivation trainer" rhetoric coming out of obesity-infested America is tiring.
You sound like there is only two extremes: Couch potatoes and people that run a marathon every weekend. There is actually a middle-ground. And a not-so-small group of people is actually comfortable in that middle-ground.
You can feel relatively healthy without running around like a wound-up monkey. Step on, don't eat too much. Then you don't have to burn calories to get rid of extra fat. It almost sounds like "uppers and downers"... Mind you, I am not arguing against sports in healthy doses. But whenever I read or talk to fitness fans, I feel like I am talking to a person following a cult.