did doctor's wife turned into a blind person finally ?

The doctor's wife is the only character in the entire novel who does not lose their sight. This phenomenon remains unexplained in the novel.

I have a theory based on the doctor's wife and why she did not become blind like the rest. towards the end of the novel the doctor says he doesn't think they were never blind, just that they were as blind as before. What he means by this is that it's human nature to just worry about yourself or to do things for a selfish gain. Even though they could be before they still didn't see how corrupt the world was ; how bad things were. It took them to be physically blind in order to see or experience just how bad things are (the killing, the raping, etc) perhaps the doctor's wife didn't become blind because of her compassion; as the summary stated she was like a mother to the blind she fed them, bath them, and fought for them against those who tried to harm them. She was always shown to be a kind woman and never let the evil things in the world get the best of her; she remained compassionate. Therefore, my theory was because she was aware of the corrupt world and she never engaged in it, that when the white sickness got everyone she was excluded from it because she was the only one who saw even when no one else did.