Tell tale heart steal character sketch?

The protagonist of the "The Tell-Tale Heart" is a classic example of Poe's unreliable narrator, a man who cannot be trusted to tell the objective truth of what is occurring. His unreliability becomes immediately evident in the first paragraph of the story, when he insists on his clarity of mind and attributes any signs of madness to his nervousness and oversensitivity, particularly in the area of hearing. However, as soon as he finishes his declaration of sanity, he offers an account that has a series of apparent logical gaps that can only be explained by insanity. In his writings, Poe often sought to capture the state of mind of psychotic characters, and the narrator of this story exhibits leaps of reasoning that more resemble the logic of dreams than they do the thought processes of a normal human being.

"For it was not the old man who vexed me, but his Evil Eye." This old man's eye was likely, in realty, normal looking. It was only inside the narrator's warped imagination that the man's eye was bothersome.