3-D printed spectacles: potential, challenges and the future.

Three-dimensional (3-D) printing offers the potential to custom-produce a wide range of manufactured objects and improve manufacturing processes. The additive manufacturing process involves material (resin, metal, ceramics or biological cells) being deposited layer upon layer, which is fused to create a 3-D object. While 3-D printing has been readily available in the aerospace and automotive industries, and is being used increasingly in the medical field, its potential for optometry and ophthalmic optics has rarely been discussed in depth.