Critics maintain that Borges innovated as a result of `progressively losing his vision until he became totally blind at age 55. His first book was the poetic anthology "Fervor de Buenos Aires," a work of his youth. The distinguished U.S. Latin Americanist Robert G. Mead maintained that "Fervor de Buenos Aires" was Borges´s best work. If this rather surprising opinion is true, then Borges wrote his finest book when he could still see!
Now, his mature invention of his famous science-fiction short stories, wherein the scientific premises are drawn chiefly from theology or philosophy, took place when he was going blind. While I appreciate the avant-garde "Fervor de Buenos Aires" in its original version (as opposed to the mature revision), I believe that "Ficciones" and "El Aleph," along with the other short story and poetry anthologies of his maturity, are more universal. To what degree is this universality a product of blindness? To the degree that Borges´ loss of spatial perception was replaced by a heightened perception of temporality, his main theme in the mature works. Can we assume without question that this compensation actually took place? Borges loved to hide behind his fictional creatures and don endless masks. I firmly believe, therefore, that we will never know with certainty. In sum, I would maintain that this question, which is excellent, is impossible to answer. I would welcome other opinions of those who know more.
I always thought that his genius was somehow stimulated by going progressively blind. It is well known that many heightened abilities can result from deprivation so even though it´s impossible to know (just like most "if" kind of questions), it seems very likely to me that the answer is "probably not" ;)
Perhaps some clue might be revealed by cross comparison with other blind poets/authors. If commonalities emerge then this might bear further investigation. What for example is Milton's life history relative to his literary output? Does anyone have other (blind) authors to add to this list?