I was diagnosed type 2 in Jan. My first noticeable symptom was my long distance vision deteriorating quite significantly (promptly followed by increased thirst/urination).
When confirmed, I was put on Metformin. This sent my vision the other way, and my short distance vision was greatly reduced.
This possibly happening was something my Doctor didn't mention to me, and when I raised it with them, they said it was unlikely due to the Metformin. I now know this to be wrong.
Due to my work, and to continue working in had to have an eye test and buy new, temporary glasses.
Fortunately my vision is back to normal now, but at the time it was very stressful.