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

Perhaps the vulture eye is an omen, reflective of what is to happen to the narrator.  For, the narrator declares, "Whenever it fell upon me my blood ran cold." And, so, the narrator becomes disturbed in a cold premonition of evil to come.  Thus, he creates a rational for killing the old man whom, he declares, he loves. He must be rid of the eye to which he ascribes evil:  "For it was not the old man who vexed me, but his Evil Eye."

In his stories Poe applied a technique which he termed "arabesque."  This arabesque is a twisting and turning of details in a horrific way.  In "The Tell-Tale Heart," it is, indeed, the heart that tattles on the evil-doer.  However, rather than being the heart of the victim as the narrator imagines, it is the beating of his own heart that the narrator hears, his own conscience which he tries to silence long before the murder. This guilt is what causes the narrator's "blood to run cold" in the beginning when he sees the vulture's eye.  For, in an arabesque, the narrator sees already reflected in the eye the murder which he will later commit.  That is, he sees in the vulture eye of death, the evil which his soul already knows before the deed.