Canadian researchers have developed a digital manufacturing platform that could one day allow patient-specific contact lenses to be 3D-printed in under 20 minutes.
The award-winning innovation paves the way for specialised lenses to be designed, manufactured, and dispensed during a single visit to the optometrist.
While soft lenses – produced in a range of sizes and shapes – are suitable for many contact lens wearers, patients with irregularly shaped corneas often require rigid lenses. Finding the right fit can require several appointments over weeks or months before patients receive lenses that fit properly.
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
Researchers in the University of Waterloo’s Department of Chemistry believe a newly developed silicone material, and advanced manufacturing techniques, will overcome these challenges.
“We are very excited about this work because it brings us closer to contact lenses that are truly personalised,” 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.”
Silicone, widely used in contact lenses, is generally not compatible with 3D printing. So, the Waterloo team developed a new hydrophilic silicone formulation.
“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, from Waterloo. “The novel hydrophilic silicone material we created, combined with our manufacturing process, produces smooth, transparent lenses that are comfortable to wear.”
Because 3D-printed objects are built layer by layer, tiny stair-step imperfections can form on curved surfaces and reduce optical clarity and wearer comfort. To overcome this, the team developed an ultra-thin, non-contact coating process that smooths the surface without altering the customised shape of the lens or compromising its optical performance.
The team is preparing for in vivo studies and advancing the technology towards commercialisation.
The project recently received a Gold Medal at the Shanghai International Exhibition of Inventions.
