funkyDuck has an interesting interpretation.  I didn't know quite what to think of the film.  It began darkly, rain obscuring our view as a vehicle with an unknown driver drove through city streets.  That blurred vision continued with the young woman's eye disease and impending blindness (blind to what?) and the graininess of the black and white photography kept things always just out of focus.  But that's the way we want it, because the hardships of street life--the cold, the hunger, the filth, and the drugs to curb the gnawing pain--are more than we want to see.