What is the doctor's wife's first reaction when they regain their sight?

When the rest of the people of the city begin to regain their sight, the doctor's wife worries that she is going to lose her own. Why? The doctor's wife thinks that she was spared so that she could bear witness to what had happened. It is not so much that she was meant to help the people, but rather to see what they had done, what they had become and to remember. If this is the case, then she has no reason to keep her sight once the others have regained theirs. Luckily for her, this does not turn out to be the case.