I published a paper in 2007 about retinal curvature and geometry of image formation. In revised version the paper has appeared on the Journal "Brain Research":
P. d'Alessandro , "On Global Geometry of Image on Eye's Back”, LNCS 4729, BVAI 2007, Springer Verlag, Berlin, 2007;
Revised version: "Retinal Curvature and geometry of image formation" Brain Research, August, 2008.
In the paper I suggested a device with hemispherical focus back. I was unaware of these attepts despite the usual searches with MathSciNet etc.
The eye and its optics are much more complex. There are many optical surfaces and the lens is altogether aspherical, variable geometry, and gradient index of refraction. There are many other issues involved in our visual perception, which I analyze in my paper.
I think that the cameras should be true to our visual world which is light years far away from current technology. Thus I hope that future cameras will use curved backs like our eye and will encompass many other techniques that nature adopted in our eye.
Cheers
Paul