As a matter of fact, according to what the book says, diabetes will lead to eye disorders, for example, double vision. Well, you might get puzzled, why? Ok. Diabetes will affect your eye system, which means that some eye problems will emerge if your diabetes get worse. So, as to your description, it is possible that diabetes led to your double vision. Alright, sorry to know that you have such disease, but life goes on right? Just have some optimism ok? Perhaps there are more miracles waiting for you. Wish you healthy life.
Yes, the diabetes may cause the high blood pressure which will indirectly cause the high eyes pressure. The unstable eye pressures may cause the double vision. You'd better go to see the doctor and keep the blood pressure in the normal state. Or else, the double vision will let you feel discomfortable.