Atticus's glasses best symbolize his character in TKAM. The glasses represent his physical weakness:
He was nearly blind in his left eye, and said left eyes were the tribal curse of the Finches. (Chapter 10)
But his glasses also represent his strength. Atticus has been able to overcome his bad eyesight, seeing the world around him much more clearly than anyone else in Maycomb. Scout and Jem first believe that the glasses make Atticus seem unmanly, but they eventually learn that despite his bad eyesight, he was a crack marksman with the rifle, earning a reputation as the "deadest shot in Maycomb County" as a youth. Later, he put down the gun, and despite his bad eye, recognized that
"... God had given him an unfair advantage over most living things." (Chapter 10)
Before killing the mad dog with a single shot between the eyes, Atticus "dropped them [his glasses] in the street" where Scout heard them crack. This may have been Atticus's way of giving the dog a fighting chance, and it symbolized the necessary return to violence that the situation called for. The glasses serve as a symbol of intelligence and social clarity. It is clear that Atticus is color blind when it comes to the races, and he is both the most successful attorney in town and Maycomb's representative to the Alabama legislature, running unopposed each election. He treats all people--black or white, male or female, child or adult--with respect, and
"Atticus Finch is the same in his house as he is on the public streets." (Chapter 5)
Atticus knows that he is the man the people of Maycomb come to when they have a problem, but he is also able to communicate with the common man. During his summation to the jury in the Tom Robinson trial, he removes his watch and chain--and his glasses--signifying that he, too, can relate to the jurors dressed in overalls and work clothes. Wiping his glasses clean of the perspiration that blurred his eyes, he returned them to his face so that he could more clearly see the jury and so that they could better see him: The man who was the conscience of the town, but a man with whom, on this day, the jury could not see eye-to-eye.