Blindness is the story of an unexplained mass epidemic of blindness afflicting nearly everyone in an unnamed city, and the social breakdown that swiftly follows. The novel follows the misfortune of a handful of unnamed characters who are among the first to be stricken with blindness, including an ophthalmologist, several of his patients, and assorted others, who are thrown together by chance. The ophthalmologist's spouse, "the doctor's wife," is inexplicably immune to the blindness. After a lengthy and traumatic quarantine in an asylum, the group bands together in a family-like unit to survive by their wits and by the good fortune that the doctor's wife has escaped the blindness. The sudden onset and unexplained origin and nature of the blindness cause widespread panic, and the social order rapidly unravels as the government attempts to contain the apparent contagion and keep order via increasingly repressive and inept measures.
The first part of the novel follows the experiences of the central characters in the filthy, overcrowded asylum where they and other blind people have been quarantined. Hygiene, living conditions, and morale degrade horrifically in a very short period, mirroring the society outside.
Anxiety over the availability of food, caused by delivery irregularities, acts to undermine solidarity; and lack of organization prevents the internees from fairly distributing food or chores. Soldiers assigned to guard the asylum and look after the well-being of the internees become increasingly antipathetic as one soldier after another becomes infected. The military refuses to allow basic medicine to be delivered, which ensures that a simple infection becomes deadly. Fearing an imminent escape, soldiers shoot down a crowd of internees waiting for a food delivery.
Conditions degenerate further as an armed clique gains control over food deliveries, subjugating their fellow internees and exposing them to violent assault, rape, and deprivation. Faced with starvation, internees battle each other and burn down the asylum, only to discover that the army has abandoned the asylum, after which the protagonists join the throngs of nearly helpless blind people outside who wander the devastated city and fight one another to survive.
The story then follows the doctor's wife, her husband, and their impromptu “family” as they attempt to survive outside, cared for largely by the doctor’s wife, who can still see (though she must hide this fact at first). At this point, the breakdown of society is near total. Law and order, social services, government, schools, etc., no longer function. Families have been separated and cannot find one another. People squat in abandoned buildings and scrounge for food. Violence, disease, and despair threaten to overwhelm human coping. The doctor and his wife and their new “family” eventually make a permanent home in the doctor's house and are establishing a new order to their lives when the blindness lifts from the city en masse just as suddenly and inexplicably as it struck.
