I need to write an essay on Lord of the Flies. What do Piggy's glasses represent--is it knowledge?--and what happens to them through the story?

Piggy's glasses absolutely represent knowledge and
intelligence. Piggy is undeniably the most sensible and learned boy on the island in
Lord of the Flies, and his suggestions and reasoning are usually
sound. Unfortunately, Piggy is not taken seriously, primarily because of his size,
asthma and superior intelligence. The glasses also represent the scientific advancements
of the modern world the boys have left behind: In addition to improving Piggy's
eyesight, they also serve as the source of fire, since the lenses can provide a flame
when reflected by the sun. The glasses also represent the boys' best chance of survival,
the source for both the signal fire and a way to cook the wild pigs which the boys hunt.
The glasses are eventually broken and then stolen from Piggy, but they remain a valuable
possession when they end up in Jack's hands.