Technology is still in the early stages.
A Dutch firm has developed 3D technology making it possible to print objects in a transparent material with a precise shape and a surface that is smooth enough to be used as a lens. LUXeXcel has used it to print some reading glasses. These are not yet as good as prescription spectacles, but in time the company expects to be able to print prescription lenses for glasses from a computerized eye scan. “Since the 3D printer could make not just the lenses but the frames as well,” reports The Economist, “it could lead to bespoke glasses being printed on demand at high-street stores.”