Cars line up at a traffic signal while their drivers wait for the light to turn green. When it does, one car does not move. Horns honk, epithets are muttered, drivers waiting behind the stationary car finally get out to investigate, then pound on the driver’s side window. There, they behold a man waving his arms and turning his head side to side. Then they open his door to hear him exclaim, “I am blind.” So begins “Blindness,” the late Portuguese writer José Saramago’s powerful, wholly original 1995 novel that explores a dystopian world in which blindness descends first on…