David, that's how I was dx'd, too. Mine flip-flopped to the extreme opposite of what it normally was in the space of an hour. My optometrist, who was treating my glaucoma, said my blood sugar was probably high and I probably had diabetes and she was right, it was over 300 when my regular doc did a finger stick.
Dedene, it took several months for my eyes to straigten out, even though I got my blood sugar down pretty fast by going very low carb right away and taking metformin. Eventually, I had to dig out my older glasses and that's what I'm still wearing today.