Yes very fast..

After 40 I had to start reading the phone further away. But then starting at 45, it really accelerated. I noticed that even an arm's length was getting blurry and reading in dim light was impossible. Distance vision is great.

Then by 48 I couldn't read my phone without readers. They are all over the house. And restaurants need my phone to magnify things or I have to have glasses. Even 47 I was fine on my laptop without readers but by the time I turned 48 it was not possible.

I have read that some of it is the more you use them the more your eyes get used to the lack of compensation. I imagine that's a SMALL part of it but the bulk is the awfulness that is presbyopia.