I've heard it described as if someone flicked a light switch, one day your vision just doesn't work like it used to. While my experience is not so sudden or dramatic, it does seem like it happened suddenly.
It used to be that I could read in even the worst conditions, including twilight and by passing street lights (I used to read in the car as a kid when we went on long trips). I still retain much of this ability. Indeed, as far as distance goes I've still got 20/20.
It's the damned fine print, you see.
I used to be able to read even the smallest print, even up close to my face. Now stuff's gotta be a little bit away from me, not at the end of my arm or anything crazy, just away from my face. And the tiny print, case in point the date on my Stauer watch, seems indistinct unless I catch it just so.
I've looked at reading glasses one or two times before, not because I had a problem but more out of curiosity. So about a week ago, I was in the supermarket and having trouble reading something fine on a product off the shelf or the date on my watch (I can't remember), when I remembered that they sold reading glasses. When I got there I tried the lowest power setting +1.00
Not only could I read the date on my watch with ease (I'd forgotten that it should be that easy), but I noticed for the first time that the numbers printed on the face were not in a normal font, but in a retro 1920s style (fitting the style of the watch).
So now I've got reading glasses, which I wear on the rare occasion that I just can't make something out for the life of me.