I think low blood sugar and low blood pressure can independently of each other cause double vision. If you have BOTH at the same time
the effects may be increased. Also increased blood viscosity may be a culprit?

I'd check your blood pressure at home with a cuff when you have this effect, and see if there is a correlation.

I also get vision changes from MSG.

I think if you journal your episodes during the day, you might correlate to food (hunger), or low pressure.

Blurred vision also comes from anticholinergic drugs. OTC things like Benadryl and Imodium, and RX things too. I don't recall on your list however, that you sent me, an anticholinergic drug.