In "The Tell-Tale Heart," what ritual had the narrator performed for seven successive nights?

The narrator of "The Tell-Tale Heart" lives with an older man, a man he claims to love, a man who "had never wronged [him]."  It is possible that this man is the narrator's father, but we never find out for sure.  The narrator, however, is particularly disturbed by one of the old man's eyes.  "It resembled that of a vulture -- a pale blue eye, with a film over it," and when the old man...

The narrator of "The Tell-Tale Heart" lives with an older man, a man he claims to love, a man who "had never wronged [him]."  It is possible that this man is the narrator's father, but we never find out for sure.  The narrator, however, is particularly disturbed by one of the old man's eyes.  "It resembled that of a vulture -- a pale blue eye, with a film over it," and when the old man looks at the narrator, the younger man's "blood ran cold."  Since the narrator describes the eye as having "a film over it," it seems likely that the old man suffers from cataracts in that eye, an ailment associated with old age.  Further, because the narrator compares the eye to a vulture's, and vultures are associated with death, it is possible that the old man's eye serves as a reminder of the narrator's own mortality -- an apparently unwelcome thought.  Thus, he determined to kill the old man in order to never have to see that terrible eye (and so be reminded of his own inevitable death) again.

In order to accomplish this goal, 

every night, about midnight, [the narrator] turned the latch of [the old man's] door and opened it -- oh, so gently! And then, when [he] had made an opening sufficient for [his] head, [he] put in a dark lantern, all closed, closed, so that no light shone out, and then [he] thrust in [his] head.

The narrator claims that it took a full hour just to insert his head into the room, and he moved very slowly so as not to wake the old man.  Midnight is also often associated with death, because it is the death of day, so it seems particularly appropriate that the narrator would begin at this time each night.  Once his head is in, he opens the lantern "cautiously -- oh, so cautiously [... so] that a single thin ray fell upon the vulture eye."  However, each night "for seven long nights," the eye was closed and so the narrator could not kill the old man.

On the eighth night, the sound of the lantern clicking as the narrator's finger slips wakes the old man.  After waiting an excruciatingly long time, the narrator opens his lantern, its light falling "full upon the vulture eye" so that he sees the "hideous veil [...] that chilled the very marrow in [his] bones," and he commits the murder.