In "The Tell-Tale Heart," what might the vulture's eye symbolize?

The narrator
tries to justify his murder of the old man by blaming it on his "vulture" eye, the old
man's staring blue eye covered with a film. The eye creeps the narrator out, and because he
describes it as vulture-like, we know he associates the old man with death. He seems to believe
that, like a vulture, the old man is waiting for him to die so he can pounce on him and in some
way metaphorically devour him. Or perhaps the care-taking the narrator has to provide feels like
being devoured.

This assertion of a vulture eye seems, given the context, to
be a classic case of psychological projection. In projection, we deny we feel certain impulses
that are unacceptable to us. Instead, we attribute them to other people.

We
know that the narrator wants to murder the old man because he acts on this impulse and does so.
However, this is an unacceptable desire, and as the story shows through the beating heart, the
narrator feels intensely guilty about it. He knows it is considered immoral in our culture to
murder a vulnerable older person who can't defend himself. Therefore, the narrator has to
project and envision the old man as an existential threat to his own life and being. The vulture
eye symbolizes this. By seeing the old man as ready and waiting to devour himrather than vice
versathe narrator can ethically justify his murder: after all, it now becomes, on an unconscious
level, self defense.

The narrator clearly has not thought this all out: as
psychology would tell us, this all occurs unconsciously. The tip off is theof the eye as vulture
like.