Peridot puts these on for every excuse she can find. They’re her official “doing science” goggles. Lapis got fed up with rounding a corner and finding Peridot at crotch-height with x-ray specs, so she started hiding them. Peridot just kept showing up with them again the next day. Lapis hid them in more and more outlandish places. Peridot kept acting like nothing had happened, and kept showing up wearing the damn goggles. It was driving Lapis to distraction, until, eventually, she witnessed Peridot forget that her goggles were already on her head, give up on finding them, and sit down to make a new pair on the spot. She’d never even noticed that Lapis had been stealing them.