Unfortunately my eye sight in my right eye is beyond the adjustable range of the dioptic.
Is it the same with your left eye? If not, perhaps you could train yourself to compose your pics with your left eye? I thinks I've read some comments about that here in the forum.
Easier said than done, of course, I'm 32 and luckily I still don't need glasses of any kind, as a right handed person it's only natural for me to use my right eye, but I guess I would give a try at composing with my left eye if I had better vision with it.
BTW, my sister is left handed and tells me that she doesn't care much and that she's already used to handling right handed oriented things after a lifetime doing so, but I think it's a bit unfair, there's a good deal of left-handeds out there, millions, and well into the 21st century there're still hardly any products specifically designed for them. Having no choice in the matter, I think it finally becomes natural for them to find, for example, the shutter release button in the right, but it doesn't take a genious to figure out that if the mayority of people were left handed, shutter buttons would be in the left.