Piggy's glasses symbolizes science and technology
1. " His specs-use them as burning glasses!" (Golding 36)
Jack, Simon, and Piggy are trying to find some way to make a fire. Jack comes up with the idea to use Piggy's glasses.
2. " Didn't you see, Piggy?" " Not all that well. I only got one eye now. You ought to know that, Ralph." (Golding 180)
Ralph is talking to Piggy because he doesn't think that Piggy saw anything.
3. " We don't want another night without fire." (Golding 186)
Piggy is giving his glasses to Ralph so they can make a fire. The reason why is that the signal fire went out and they want to recreate the fire.