need some advice with rigging bezier curves

I have a set of eyes and eye brows done with bezier curves. I have an upload of the eyes so you can see how they are.

I like how shape keys work, easy to create and give good results for bezier. The problem is once I get one eye looking good, in order to make the other eye do the same thing, I have move around the curves on that as eye as well, starting all over again and it never turns out like the first one.

It seems that the mirror feature with shape keys only work when the mesh is all one piece, this doesnt apply for me.

an armature rig requires a mesh to work well with weight paint and still wont yield as good of results as shape keys.

Is there any way of mirroring the bezier from one eye to another, without using the mirror modifyer? (the eyes will not always be exactly the same on both sides for all expressions)

I appreciate any suggestions

did you try to scale z -1 to duplicate your eye reversed?

Thanks for the suggestions, sadly that had no effect at all. Just to make clear, I am not sure is this is understood (I am not implying that your idea was bad, I only know about a third of blender so I dont understand how blender does a lot of things), but the eyes are made up of one object. This object is made up 6 separate bezier curves. So a lot of techniques of copying mesh data and positioning from one side to another wont work here.

Please keep the suggestions coming, any ideas are apprecitated.