Bad vision

So, I went into the eye doctor the other day to have my eyes checked. I've been noticing that over the past few years, they've degraded a bit. My vision degraded all the way down to 20/20 in one eye and "20/15" in the other. (I used quotes because I think the doctor just used a familiar term, as the normal correct term is 20/16.) Normal uncorrected human vision is actually 20/12 to 20/16. 20/20 is considered the low end of normal, but it is actually slightly off. This is what've been noticing. My eyes being slightly off. So, as it seems, I've just been spoiled with really good vision before, and now I just have good vision.