razzle, I've had the suddenly out of focus experience too (and my blood sugar is, apparently, fine -- don't know the numbers, but I was told by a doctor, who looked a bit disappointed, that "well, your body processes sugar and fat very well.)

It happens whether I eat sugar or not, though.

About a year ago in my eye exam, my prescription had weakened drastically -- after remaining stable for 40 years! I was fine looking through the doctor's whatchamacallit, but when I got home, I couldn't see anything -- not near, not far, not middle. So I went back, and it was, magically, what it had always been. "You must be diabetic!" he said. I went to another doctor and the same thing happened -- she, however, noticed that the lens was steamy, hence blurring my vision.

It made me think this all may not be an exact science

Thanks, Nat, for the info about the omega 3s. THAT makes more sense!