A man suddenly goes blind in his car while stopped at a red light. He can see nothing but a bright whiteness. A young man drives him to his home, and helps him to his room, then steals his car. The man's wife comes home and takes him to an ophthalmologist. In the waiting room is a woman with dark glasses who has conjunctivitis, an old man with a black eye patch, a young woman, and a boy with a squint and his mother. The doctor is unable to find any problems with the man's eyes.

That evening at home, the doctor suddenly goes blind as well. The next day, the Ministry of Health sends an ambulance to pick him up and take him to quarantine. His wife helps him pack and secretly packs for herself. When the ambulance arrives, she lies and says she has gone blind as well so they must take her.

The quarantine is in an abandoned mental asylum. The doctor, his wife, the first blind man, and car thief, the woman with the dark glasses, and the boy with the squint are all there. On the other side of the building those who were in contact with the blind are interred until they also become blind. Food will be delivered daily by the army - if they try to escape they will be killed. The doctor's wife can still see, but only the doctor knows this. The car thief gropes the woman with the dark glasses, and she kicks him in the leg, puncturing the skin.

The next day, internees arrive from both outside and the contaminated wing. The first blind man is joined by his wife. The car thief gets very sick. In the night he tries to go to the gate to ask the soldiers for medicine. They shoot him. He is buried in the courtyard the next day.

Food does not come regularly, but it does come. One day a group is waiting in the hall for the food to arrive. The soldiers see them, panic, and open fire, killing nine people. They are buried in the courtyard. Within a few days, there are over 240 blind people (the asylum only has 240 beds). Among them is an old man with an eye patch - the last of those in the ophthalmologist's office when the first blind man arrived. The next day a group from the third ward on the left (opposite the doctor's wife and her group) surrounds the food, holding weapons, including a gun. They will distribute the food from now on, but only if it is paid for. The doctor's wife challenges them, and the leader threatens her, saying his will not forget her voice. She says she will not forget his face.

The first payment is all the valuables in the internees possession. They receive food but it is not enough. Within a week or so, they say they need woman. The ward with the doctor's wife is the third in line. Meanwhile, the asylum has become extremely disgusting, with excrement covering the walls, floors, and residents. When their time arrives, seven women from the ward, the doctor's wife, the wife of first blind man, the woman with the dark glasses, a woman with insomnia, a woman we know nothing about, the young woman from the ophthalmologist, and a chambermaid. When they arrived at the third ward on the left, they were raped by the men repeatedly through the night. The woman with insomnia died on the way back to their ward.

Four nights later it was the turn of the next ward. The doctor's wife snuck in with the group of 15 women from this ward. She came up behind the leader, told him "I have not forgotten your face" and stabbed him in the throat with a pair of scissors. Chaos ensued at this, and she had to fight to free the women who had been forced to come here. They all succeeded in fleeing. The group, however, now refused to give food to anyone else and barricaded themselves into their ward. Food also stopped arriving from the military.

As the days pass the internees begin to starve, and so the old man with a patch leads an attack against the ward with the food. The attack fails and two people die. The woman who the doctor's wife saved sneaks back to the ward with a lighter, and sets it on fire. The fire quickly spreads to the entire asylum, and the blind internees are forced to flee to the gate. The doctor's wife leads her husband, the boy with the squint, the woman with dark glasses, the man with the patch, the first blind man and his wife out of the asylum (she reveals to them at this point that she can still see), and they discover the soldiers are all gone. They leave the asylum.

The next day they seek shelter in a store while the doctor's wife goes in search of food. She learns the entire city is now blind. She finds a supermarket with a store room at the bottom of a flight of stairs with food. She gathers what she can and runs through the store to avoid the blind people walking around. She breaks down and weeps and a dog licks her tears away. The dog joins her group.

Fed, the group makes their way to the doctor's house, which it turns out has remained intact. There they are able to find clean clothes, and avoid the nasty smells that plague the city. It rains, and the group bathes themselves. The doctor's wife begins to read to them at night. The woman with dark glasses and the old man with a patch confess their love for each other. The doctor's wife returns to the supermarket for food, only to find that when she ran out, the others realized there was food there, and rushed it. They fell down the stairs, and many people were killed. She is devastated.

That night, while reading, the first blind man suddenly realizes he can see. Slowly, the others in the group regain their sight, as does everyone in the city.