In Lord of the Flies, what object symbolizes Piggy's weakness? How does Golding show that he is weak, and why?

One important weakness readers uncover about Piggy is his
eye sight and his seeming lack of self esteem.  The fact that he must wear glasses, or
"specks" as they call them in the novel, demonstrates that society often lacks the
quality of seeing things clearly.  In the boys' society in Lord of the
Flies, some the boys don't want to see things clearly (Jack and his group). 
Piggy's glasses represent wisdom and common sense.  Where Piggy is calm and thoughtful
about situations presented, the others are playing dangerous games that culminate into
murder and evil.