It could be that he became blinded so that he could relise he actually had the ability to see the machines and such in that weird orange code which looked awesome.
Like if you go deaf your sight will get better and vice versa, except he has this extra ability, when in the "real world" he was too busy actually concentrating on his normal vision to notice this ability, or he wasn't ready to accept it.
For those of us who’ve read “Dune” and “Dune Messiah” Neo really, truly going blind was a shock. A rather soul-chilling taste of things to come.
Blindness in myth and fairy tales are often associated with “second sight.” You know, blind oracles, the blind hermit, some blind fortune tellers from a Greek legend on.. was that… Hercules or…?
Anyways: Without the blindness Neo wouldn’t have realised his ability to “see” the electric and magnetic fields, and energy fields of the machine world.