I've been dealing with double vision for 10 years. I too have invested a small fortune in prism glasses, ranging from about 5 diopters of prism to 12 prism diopters. Wearing a patch didn't work out and I tried taping my one lens but wasn't able to adjust. I've managed with the prism glasses, but the double vision was often the worst symptom to deal with when I was working. I certainly understand what you're going through. I hope you find a solution that works for you.