I'm not sure that the refraction of a lens is mathematically invertible/reversible? As I understand it, the problem with my eye is that my lens doesn't focus a

I'm not sure that the refraction of a lens is mathematically invertible/reversible? 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.