The optic nerve is a bundle of nerves like several other nerve bundles in the body. I suspect that it has more nerves than any other simply because it must convey a few million pixels. I have heard of no suggestion that a single axon in the optic carries information for more than one pixel. For most and perhaps all purposes of the optic nerve adjacency of pixels is necessary to achieve from one end to the other. Nerves that connect various visual processing areas in the brain have even more complex integrity requirements, but perhaps less stringent. The latter are shorter too which helps.
I know two techniques to wire up the optic nerve and neither seems highly plausible:
The cryptanalysis of this system assumes many encrypted images and looks for pairs of pixel locations that agree more often than most pairs. This suggests that such pairs occurred close to each in the plain image. Enough such discoveries will piece together the whole picture. The same algorithm might conceivably work for the optic nerve.