No wonder I'm having trouble seeing well

I was going through some papers up on the shelf of the computer desk and found a prescription from two years ago for the eyeglasses I'm wearing right now, and they are way too strong for distance, but too weak of a bifocal. If I understand these things, my right eye is listed as -8.00, the left is -7.25, and the bifocal for both is only +1.75. I don't have a copy of my current prescription from the other day (I need to ask for that when I go to pick up my glasses), but I do remember the right eye was -7.00 and the left was about -6.50 or -6.75, and the bifocal was going up to +2.50. Of course, while I know these are my last glasses, and the prescription is the last one I had for glasses that I filled, the actual bifocal on the glasses is 2.0--I know that because it can be read if you look at them carefully, and they said so when they examined them the other day. So I don't understand why the disparity. But it's probably helped some, too. Still, no wonder I couldn't see small print or my phone without taking the things off. Meanwhile, I checked the contacts I bought at my last appointment. The contacts that were giving me trouble are actually about the same as the new prescription, so I'm not understanding what's wrong, unless maybe the bifocal on them (they're multifocal) is off, but it's listed as high, so that should be good. I may try them again. Maybe the last prescription wasn't bad after all. But I know for certain that the exam for this one was good as far as my blood sugar, while the other was up. We'll see. And I'm not sure if the astigmatism numbers (the cylinder and axis on the prescription) change at all with blood sugar, so that could be part of it.