I've had good eyesight all my life, until recently. Now I need glasses to read (which I spend lots of time doing) and now, in the past few months, I need them to use the computer.
In the past, due to a diagnosis of MS (Multiple Sclerosis) I had a bout with Optic Neuritis, where my vision dimmed, everything I looked at was doubled, and out in the sun it was extremely hard to focus on anything.
I recovered, thankfully, but never forgot that vulnerable feeling. Now, I no longer take my vision for granted, and use safety glasses if I'm going to be doing something somewhat dangerous, and sunglasses to protect from the glare off snow or water.
With age, our eyes tend to become more stiff and harder to focus with, which makes fine work like reading or needlework much more difficult. Try threading a needle in the dark, if you want to know what it's like!
Another unfortunate side effect for me is lack of balance. As the center for balance in your brain is directly beside the one for vision, exercises can be used to make both things stronger. They're simple, and only take a few minutes a day, but they are incredibly effective.
Using glasses to go about everyday life used to be a pain - just ask my parents, who both wore glasses all the time. Dad had been riding a bike and a bee flew in his eye, a long time ago.
As long as I knew him, his glasses were part of him. Mum used to have good eyesight, especially long sight, where she could spot things in the distance with no problem.
Now, she tells me, everything is double - birds in a flock seem to be many more than what I see.
What I know now is that everyone has different vision, but it's no less precious to us all. Treat your eyes well, and give them preferential treatment, every day.