From Twinfinite: “Throughout Nier Replicant there are plenty of questlines that require you to get ahold of certain raw materials to either progress or complete them. The Broken Lens is one such piece of scrap that youre going to want to get your hands on as soon as you can. Here is everything you need to know about how to get Broken Lens in Nier Replicant.”
Source: N4G PC Nier Replicant: How to Get Broken Lens