A new silicone lets 3D printers turn out custom

A team at the University of Waterloo has built a digital manufacturing system that prints custom contact lenses in roughly 20 minutes, raising the prospect that a patient could be measured, have a lens designed, and walk out wearing it after one clinic visit. The approach pairs a purpose-built silicone material with additive manufacturing, and it earned a Gold Medal at the Shanghai International Exhibition of Inventions in June 2026. Replacing weeks of fittings with a same-day workflow The bulk of contact lenses on the market are produced in a fixed set of standard shapes and sizes rather than shaped to the individual eye. Soft lenses work well enough for a large share of wearers, but people whose corneas are irregularly shaped frequently need rigid lenses to see clearly, and dialing in the correct fit for those lenses can stretch across multiple appointments over weeks or even months. The Waterloo platform, developed in the university’s Department of Chemistry, is designed to compress that cycle. It ties together three components: software that designs each lens, a novel silicone formulation, and the printing and finishing steps that turn a design into a wearable product. “We are very excited about this work because it brings us closer to contact lenses that are truly personalized,” said Dr. Shirley Tang, professor in Waterloo’s Department of Chemistry. “Our technology produces lenses with patient-specific surfaces for a precise fit while delivering the optical clarity and mechanical performance expected of commercial contact lenses.” Reformulating silicone so it can be printed Silicone is a mainstay of contact lens production because it is safe for the body, well tolerated, and lets a high volume of oxygen reach the eye. The catch is that standard silicone does not lend itself to additive manufacturing. The Waterloo group got around that by creating a new water-friendly silicone recipe tailored for printing while still holding onto the characteristics a lens needs. The design software handles the two sides of the lens separately. “Our software designs a lens with an inner surface that precisely matches the patient’s cornea and an outer surface that provides the required vision correction,” said Dr. Sayan Ganguly, a chemistry research associate at Waterloo. “The novel hydrophilic silicone material we created, combined with our manufacturing process, produces smooth, transparent lenses that are comfortable to wear.” Anything built up layer by layer tends to show faint stair-step ridges on curved surfaces, and on a lens those ridges can blur vision and irritate the eye. To counter it, the researchers created an ultra-thin, non-contact coating step that evens out the surface without disturbing the lens’s tailored geometry or degrading its optics. Lab tests indicate the lenses are biocompatible, and the team is gearing up for in-vivo trials. A provisional patent has been filed on the hydrophilic silicone, with a full application in the works. The group is also collaborating with the Centre for Vision and Eye Research, a joint institute run by Waterloo and the Hong Kong Polytechnic University, to push the technology toward market. The study was led by Sayan Ganguly serving as lead author, alongside co-authors Astrid Stinson and Fatemeh Parniani, and senior author Xiaowu Shirley Tang, who supervised the project. The work was supported by two grants from the Natural Sciences and Engineering Research Council (NSERC) of Canada awarded to Tang, with additional funding from Hong Kong’s InnoHK initiative. Their study, “Patient-specific hard contact lenses fabricated by vat photopolymerization printing and non-contact fluidization coating,” appeared in Materials & Design. Limits and challenges The technology is still at an early stage, and a few practical gaps remain. The coating smooths the printer’s tiny “stair-step” ridges but doesn’t remove them completely, dropping the step height from about 5 microns to roughly 1.2 microns. The lenses let through enough oxygen to qualify as rigid gas-permeable, though not as much as the best products on the market. And at 12 minutes to print a lens, 15 to 20 minutes with washing and coating, the process still has to prove it can run reliably at scale. The bigger hurdles are clinical. So far the lenses have only been tested in the lab and on cultured cells, never worn on a real eye, so comfort and long-term safety are still unknown. The team also has to run in-eye trials, secure regulatory approval, and line up manufacturing partners before the lenses could reach an optometrist. For now, the 20-minute lens is a promising proof of concept rather than something patients can use. Why decentralizing the lens factory is the real prize Waterloo’s play is less about a single faster printer and more about relocating manufacturing to where the patient already is. The team is targeting the specialty and rigid-lens segment that today depends on repeat visits and off-site fabrication, the slice of the market where standard molds fail people with keratoconus, scarring, or otherwise atypical corneas. The ambition echoes earlier moves. Netherlands-based Luxexcel advanced its additive process for ophthalmic lenses from a pilot stage to shipping commercial lenses daily from ISO-certified platforms installed across the US and Europe, positioning printing as a way to sidestep the roughly 80% of material wasted in conventional grind-and-polish lens making. Its VisionPlatform combined industrial printers, lens-design software, and workflow tools to turn out lenses meeting ANSI, ISO, and FDA standards in a single step. The optical-quality hurdle Waterloo tackles has also drawn other labs. Researchers at Northwestern’s McCormick School of Engineering built a method for printing high-quality optical lenses and ran directly into the same obstacle. Their first printed lens showed visible stepping because a typical layer thickness of about 5 microns dwarfs the roughly 0.5-micron wavelength of visible light, leaving a surface too rough for clear vision. The group saw the technique feeding into customized contact lenses for people with corneas distorted by keratoconus. The direction is clear: lens making is moving out of the factory and into the clinic. Waterloo’s printable silicone and smoothing step push that shift forward. What happens in clinical trials will decide whether same-day lenses become standard. 3D Printing Industry is inviting speakers for its 2026 Additive Manufacturing Applications (AMA) series, covering Energy, Healthcare, Automotive and Mobility, Aerospace, Space and Defense, and Software. Each online event focuses on real production deployments, qualification, and supply chain integration. Practitioners interested in contributing can complete the call for speakers form here. To stay up to date with the latest 3D printing news, don’t forget to subscribe to the 3D Printing Industry newsletter or follow us on LinkedIn. Explore the full Future of 3D Printing and Executive Survey series from 3D Printing Industry, featuring perspectives from CEOs, engineers, and industry leaders on the industrialization of additive manufacturing, 3D printing industry trends 2026, qualification, supply chains, and additive manufacturing industry analysis. Featured image shows 3D printed contact lenses. Photo via University of Waterloo/Jay Mielke.