Okay. So I am looking at a couple things. I did quite a bit of research so I may have over thought this. So far I'm looking at digoxin toxicity, potassium deficiency, and dehydration, in that order. Am I on the right track? Any of these could account for her symptoms but the digoxin looks the most suspicious because of it's own side effects(including double vision, hallucinations, confusion) and it's high potential for toxicity when combined with diuretics(HZTC). HZTC can also cause blurred vision on it's own. Do we know if these were all prescribed by the same doctor? Is she using prune juice, bran cereal, or a high fiber diet to maintain gi regularity, which is common in the elderly? All of these can increase the effects of digitalis as can a salt-restricted diet that she may be on for the hypertension. I haven't listed all of my reasons for looking at these disorders as to not waste your time if I'm wrong, but if you have any questions as to my reasons, feel free to ask. Oh, and please let me know if I'm over thinking this. I tend to do that.
By the way, my drug info is from The Complete Guide to Prescription and Non-Prescription Drugs(2005 edition) originally published by H. Winter Griffith, M.D. and revised by Stephen Moore, M.D. in case you were wondering.