When the good Samaritan initially offered to help the first blind man, he had no intention of stealing his car. The idea had come to him when he dropped the blind man off at home and hurried the car thief out the door without asking for the keys back. Perhaps if the first blind man had allowed the car thief to stay, he would have been overwhelmed by his conscience and wouldn't have stolen the car. In any event, the car thief is driving around the city, nerve wracked in an attempt to avoid the police, when he decides to park the car and wait. As soon as he gets out of the car he goes blind.
At the eye clinic, the doctor finishes up with his patients for the day and calls a colleague about the case of the spontaneous blindness. They decide that it is either a case of psychological blindness or agnosia or amaurosis. Agnosia means that he can see, but is unable to recognize objects. In amaurosis, though, the brain becomes unable to process images, leading to a loss of all color. The first blind man, though, claims that he is surrounded by milky whiteness. At dinner, the doctor mulls over these problems with his wife. Later, doing research at his desk, he goes blind.
The girl with the dark glasses who was waiting at the clinic was afflicted with a minor case of conjunctivitis. The doctor prescribed her some drops and told her to keep her sunglasses on. Later, as she is meeting a client (the girl is a part-time prostitute) she goes blind.
Narratively, this part continues the "montage" technique begun in the first part. This consists of briefly showing the back stories of all of the main characters in a choppy, non-sequential format. This means that the narrative jumps from one character to the other, with no introduction or explanation. This fragmentation will be resolved latter when the story moves to the quarantine, where the characters are reunited.
We also begin to see here the kind of social and moral leveling effect that the disease has on society. The just and the unjust, the moral and the immoral are all affected equally. While the first blind man was relatively inconspicuous (neither his age nor his occupation are given) the three victims of this part are relevant because they represent a spectrum of the socio-economic scale. We thus have a well-off doctor who is morally unassailable. We also have a common thief. In between these two we have the girl who is, according to the narrator, a part-time prostitute who lives with her family. The leveling effect of the disease will lead to a certain degree of egalitarianism later in the novel.
In addition to the more literal social leveling of the disease–everyone is affected equally–there is an allegorical meaning to the egalitarianism of the disease. If we take the allegorical interpretation of the story where sight acts as a metaphor for understanding, we can see that the blindness qua metaphor for ignorance spares no one. Neither the wise doctor nor the base criminal are spared this blindness which will soon affect everyone. Read through the frame of the allegory, the reader is to understand that we are all afflicted by the same lack of understanding or insight.