IN THE SPAN of just a decade, 3D printing has evolved from a prototyping/hobbyist tool to a full-fledged fabrication technology that is reshaping industries worldwide. This article highlights the potential of using 3D printing technologies to create contact lenses for personalized eye care.

3D printing offers several advantages over conventional manufacturing methods, including fast turnaround times and lower costs for custom-tailored products. Additionally, this technology enables the creation of complex spatial designs that were previously unattainable through any other method. These advantages align very well with situations in which one-off or specialty designs are required for individual patients, such as scleral and orthokeratology lenses, where custom and personalized products are required over a one-size-fits-all solution.

It is easy to envision how a clinician could simply use a corneal topographer to capture a patient’s corneal profile (Sanchez-Tena et al, 2019), and then use the output to 3D print a customized lens. Instead of making patients wait weeks or months to receive their specialty lenses, practitioners could print them in the office during a regular visit. Alternatively, their lenses could be printed at a local clinical site for pickup just a few days later. The utilization of 3D printing would also eliminate the need to keep multiple units in stock and long-term storage.

Despite its advancements, current 3D-printing technology still has limitations. Plastics and resins are widely used, but the cost of more specialized printable materials can escalate significantly. The ultrathin and curved shape of contact lenses also makes printing challenging. The resolution of the 3D printer plays a crucial role too, because extrusion-based printing is limited by nozzle size and laser-based printing is constrained by the width of the laser beam.

Low-resolution prints, commonly observed as 3D print lines, can result in rough surfaces that cause light scattering and reduce transparency, rendering them unsuitable for optical applications. Rough surfaces could also lead to discomfort during wear. Some researchers have already demonstrated the feasibility of 3D printing hard and soft contact lenses (Alam et al, 2022; Wulff et al, 2023; Aravind et al, 2022; Alam et al, 2021; and others—full list available online), but achieving acceptable resolution remains the main challenge.

Addressing the problem of low-resolution printing can be solved by using higher-end printers, such as two-photon 3D printers capable of achieving nanometer resolutions (Ovsianikov et al, 2007; Bunea et al, 2021). However, the high cost of these printers currently limits their practical use in a clinical setting. Fortunately, given the rapid progress of 3D-printing technology and decreasing costs, it is anticipated that advanced 3D-printing technologies will likely become feasible for eyecare applications in the next decade.

In the meantime, there are alternative ways to address the resolution challenges. For example, instead of directly printing the lenses, one option is to 3D print molds for the lenses and subsequently employ conventional manufacturing methods, which would offer another way to highly individualize lens fabrication. The inherent 3D print lines on contact lenses could even serve as microfluidic channels to enhance tear flow over the lenses (Aravind et al, 2022).

In addition to technical challenges, there is a need to establish protocols for sterilization, safety, and quality control in the clinician’s office if 3D-printed devices were to be dispensed directly to patients. The issue of liability, and whether it rests with the clinician, the 3D printer, or the printer’s designers, would arise if there were adverse outcomes.

Despite the challenges that lie ahead, the progress toward a 3D-printed contact lens holds tremendous promise for improving patient care. But rather than waiting for its full realization in the future, it may be worthwhile to start exploring what other advantages 3D printing might offer for clinical practices today. CLS

References

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2. Alam F, Salih AE, Elsherif M, Yetisen AK, Butt H. 3D printed contact lenses for the management of color blindness. Addit Manuf. 2022 Jan;49:102464.
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