Why Prototype Testing Is Important for Custom Silicone Lenses
https://siliconepartsblog.huicopper.com/no-drip-valve-basics-for-cleaner-packaging-and-better-customer-use
Designing a small part can affect the whole product. A silicone lenses may look simple, but it has a real job to do. It must work with the cap, case, fluid, air path, or light path around it