From the book:
When Edward Temple was about eight or nine years old he was afflicted with a disorder of the eyes. It was so severe, and his sight was naturally so delicate, that the surgeon felt some apprehensions lest the boy should become totally blind. He therefore gave strict directions to keep him in a darkened chamber, with a bandage over his eyes. Not a ray of the blessed light of heaven could be suffered to visit the poor lad. This was a sad thing for Edward. It was just the same as if there were to be no more sunshine, nor moonlight, nor glow of the cheerful fire, nor light of lamps. A night had begun which was to continue perhaps for months, - a longer and drearier night than that which voyagers are compelled to endure when their ship is icebound, throughout the winter, in the Arctic Ocean. His dear father and mother, his brother George, and the sweet face of little Emily Robinson must all vanish and leave him in utter darkness and solitude. Their voices and footsteps, it is true, would be heard around him; he would feel his mother's embrace and the kind pressure of all their hands; but still it would seem as if they were a thousand miles away.