My glasses perscription is -1.0 -1.25 is how does the prescription relate to the 20/X number?

Question

Does that mean i have 20/40 vision, or 20/50... or what?

Answer 1

Try an eye chart .

Answer 2

There is no really direct correlation, but that puts you at about 20/40 or 60 and 20/50 to 20/70.  Together you can probably read 20/50 give or take a few letters.