I don't think it would be very practical, especially since I think it would be hard to make it work without dictating the exact distance from phone screen to eye and from camera to object being viewed. But it would be cool.
If your eyes have different prescriptions it's not going to work, but maybe you could set it up for one eye and just close the other (but then maybe it would be easier to hold the phone closer to/further from your face).
I wish I could remember enough about optics to figure this out!
And you're right that two eyes would be a problem. Even if they have the same prescription, I think the fact that the angle from the left eye to the screen and from the right eye to the screen would be different.
It seems like a monocole should be doable, at least if I dictate that they center the phone in front of their eye and the distance from their eye to the screen. But I don't know much about optics either.
As I understand it, the problem with my eye is that my lens doesn't focus a point light source (e.g. a pixel) onto a point on my retina - one consequence of which is that the point source gets smeared out over a larger area (also I have astigmatism which means my eyes aren't perfectly spherical so colours get messed up, but lets ignore that!).
You can't fix that smearing by warping the shape of the image, but maybe you could adjust the brightness of the adjacent pixels to cancel out the smeared out bit - I guess by making the adjacent pixels a little darker than they should be. I don't know if that's a solvable set of equations.
If I flip my glasses over and look through the lens backwards, my vision doesn't get twice as bad - it's actually better than no glasses at all. Not sure what that tells you other than optics is very confusing to me.