Prisms

I complained to my optometrist that I was seeing slightly double. He prescribed some glasses for me and I bought them, but they didn't help. I then began a wild goose chase, visiting several specialists who each said "There's nothing wrong with X, go see a specialist who deals with Y", until I ended up at an ophthalmologist. He examined my glasses and said "These don't do anything for you, do they?" and proceeded to prescribe glasses with a prism lens, to bend the light and correct the horizontal mis-alignment of my eyes. Seems like the logical thing, right? Why didn't the first guy think of that? Thanks to him I've used up my optical health coverage on the wrong prescription and now it's going to cost $140 for custom prism lenses. But at least I'll be able to watch TV without closing one eye.