This is a great question. As you know, Piggy's glasses are an important symbol that points to science and technology, as the boys figure out how to make fire with his glasses.
The other symbol of this chapter is the conch shell. Right from the beginning of the book, the conch was a symbol for civilization and order. The conch brought the boys together, which created for some sort of civilization and the conch also allowed people to speak in terms. From this perspective the conch also represents democracy. This conch was the hope that the boys had.
In chapter 10, Ralph holds on the conch with desperation and he hits his low point. This is very symbolic, because what we are seeing is the death of society and order. Keep in mind that this all takes place right after the death (murder) of Simon. Moreover, Jack is now in control of the island.