Custom 3D-Printed Contact Lenses

The first contact lenses were made of glass and were uncomfortable to wear all day; today, they are made of soft materials such as silicone hydrogel and are practically imperceptible when worn, but there is still a problem that affects millions of people. Those with irregularly shaped corneas typically need to rely on custom-made lenses that can cost hundreds of dollars, require several appointments, and take weeks to be ready.

Now, researchers at the University of Waterloo in Canada have developed technology that completely transforms this process. Using 3D printing and a new type of silicone, they’ve managed to manufacture fully customized contact lenses in about 20 minutes. The principle seems simple, but it requires tremendous precision. First, a detailed map of the patient’s cornea is created to generate a three-dimensional digital model. Using that information, software designs a lens whose inner surface exactly replicates the shape of the eye, while the outer surface is adjusted to provide the necessary optical correction.

That model is then sent to a 3D printer capable of manufacturing the lens layer by layer. The biggest challenge is sourcing the material; silicone is considered one of the best materials for contact lenses because it is flexible, biocompatible, and allows oxygen to pass through. These are essential characteristics for maintaining eye health; however, silicone was not compatible with conventional 3D printing processes.

To overcome this limitation, the researchers developed a new formulation of hydrophilic silicone capable of being printed with precision without losing its mechanical and optical properties. Another obstacle arose with additive manufacturing itself: objects produced by 3D printing typically exhibit small irregularities between layers—imperceptible in ordinary parts but sufficient to cause discomfort and impair vision in a contact lens.

The solution was to apply an ultra-thin coating that eliminates these imperfections without altering the lens’s custom shape, preserving both transparency and optical precision. Initial laboratory tests showed very promising results: the lenses demonstrated biocompatibility with ocular tissues and optical performance comparable to that of commercial lenses already available on the market.

Researchers are now preparing to begin real-world testing and move forward with the patenting process ahead of future commercialization.