all the light I enjoyed came through the stye
This is not easy to visualize, but Mary Shelley twice emphasizes the
presence of this stye. She appears to do so for several interrelated
reasons: in order to have a natural bulwark against the Creature's being
detected by the cottagers; to place the Creature symbolically as close to
the natural order as to human beings; and to reveal, against our visceral
repugnance at the accompanying noise and stench (if the De Lacey household
had been able to afford to keep a herd of swine), the level of subsistence
to which necessity has reduced this being after six weeks or so of his
existence.