3D Printed and Customized: The Technology Aiming to Revolutionize Contact Lenses
Contact lenses have undergone a significant evolution over the last few decades, transitioning from the early glass models to devices made with soft materials like hydrogel silicone, which are now widely used due to increased comfort and good oxygen permeability. Despite these advancements, achieving a perfectly fitted lens for the shape of the eye remains a challenge for many patients, especially those with irregular corneal geometries.
In these cases, custom contact lenses are often necessary, a process that can require numerous appointments for fitting and adaptation, as well as high costs. A research group from the Department of Chemistry at the University of Waterloo in Canada believes it can reduce time and costs through a digital manufacturing platform based on 3D printing. The goal is to create patient-specific contact lenses within approximately 20 minutes, allowing design, production, and delivery during a single visit to the optometrist. The system combines proprietary design software, a new silicone material specifically developed for this purpose, and advanced additive manufacturing techniques.
The software generates a three-dimensional model of the lens based on the patient's corneal shape. The inner surface is designed to fit precisely with the anatomy of the eye, while the outer surface incorporates the necessary optical correction. According to the researchers, this approach could offer a more accurate solution compared to lenses produced in traditional standard size ranges.
One of the main obstacles was the material itself. Silicone is considered ideal for contact lenses due to its biocompatibility, softness, and ability to allow oxygen to pass through, but conventional formulations are poorly compatible with 3D printing processes. To overcome this limitation, the team developed a new formulation of hydrophilic silicone, specifically designed for additive manufacturing while maintaining the required characteristics for ophthalmic use.
Another critical issue concerns the 3D printing process itself. Objects are built layer by layer, which can generate microscopic surface imperfections known as the 'stair-step' effect, potentially compromising both comfort and optical quality in contact lenses. To eliminate these imperfections without altering the customized geometry of the lens, the researchers developed a non-contact ultra-thin coating process capable of smoothing the surface while preserving its optical properties.
From left to right: researchers from the University of Waterloo and co-authors of the study, Dr. Sayan Ganguly, associate researcher in the Department of Chemistry, Fatemeh Parniani, Master's student, and Dr. Shirley Tang, faculty member in the Department of Chemistry (University of Waterloo/Jay Mielke).
Initial laboratory tests showed encouraging results. The lenses proved biocompatible, thus safe for interaction with ocular tissues, and exhibited optical and mechanical performances considered comparable to those of commercial contact lenses. The research group is now preparing in vivo studies, a necessary step before any potential clinical use.
In parallel, the journey towards protecting intellectual property continues. The researchers have already filed a provisional patent concerning the new hydrophilic silicone and are preparing the final application. The development of the technology is also in collaboration with the Centre for Vision and Eye Research (CEVR), a joint institute of the University of Waterloo and the Hong Kong Polytechnic University, aimed at facilitating its transfer towards commercial applications.
The project recently received a gold medal at the Shanghai International Exhibition of Inventions 2026. The technical details of the research have been published in the journal Materials & Design.