Coetzee's "Age of Iron": How Can We Judge? How Can We Know?

The cancer-stricken narrator, Mrs. Curren:

   As the other car drove off at last, the woman turned to glare at me. Her face not unattractive yet ugly: closed, bunched, as if afraid that light, air, life itself were going to gather and strike her. Not a face but an expression, yet an expression worn so long as to be hers, her. A thickening of the membrane between the world and the self inside, a thickening become thickness. Evolution, but evolution backward. Fish from the primitive depths (I am sure you know this) grew patches of skin sensitive to the fingerings of light, patches that in time became eyes. Now, in South Africa, I see eyes clouding over again, scales thickening on them, as the land explorers, the colonists, prepare to return to the deep.
   Should I have come when you invited me? In my weaker moments I have often longed to cast myself on your mercy. How lucky, for both our sakes, that I have held out! You do not need an albatross from the old world around  your neck; and as for me, would I truly escape South Africa by running to you? How do I know the scales are not already thickening over my own eyes? That woman in the car: perhaps, as they drove off, she was saying to her companion: "What a sour old creature! What a closed-off face!"