Final answer:
Piggy from 'Lord of the Flies' needs to visit Jack's tribe to retrieve his glasses, which are an essential symbol of his intellectual identity and necessary for clear vision.
Step-by-step explanation:
The character Piggy from William Golding's novel Lord of the Flies is insistent on visiting Jack's tribe primarily to get back his glasses. Piggy's glasses are a symbol of intellect and wisdom and are crucial for him to see clearly. The loss of his glasses to Jack's tribe not only impairs his vision but also represents the erosion of rationality and order on the island. His determination to retrieve them highlights his dependence on this tool for both physical and metaphorical clarity amid the chaos that ensues among the boys on the island.