Somehow I doubt that this is the entire message of the book–Saramago must be above cliche'. But this is about how the narrative ends; one by one they regain their sight, the world will recover and go on. Did the people learn anything? Was this a punishment from God? How long did the white blindness last and what made it go away? Why didn't the doctor's wife ever go blind? Why didn't anyone try to figure that out?
In other words, the book somehow left me unsatisfied.
The story may have already been made into a movie, and this is what I think it is more suited to be; a horror movie that contains the arc, the main characters, the conflicts, the resolution (or not, if you're looking for a more literary context), the blood, guts, bad government, man willing to do almost anything for survival, etc. The writing was good, but in my mind not great; though I could say that perhaps it loses something in the translation.
All in all, an okay book.
I forget who said it, but the adage is true: if you introduce a pistol in chapter 2, there better be a body by the end of the story, or the reader will feel cheated…