The tear film coating the eye offers a window into a person's systemic and ocular health, carrying biomarkers such as glucose, electrolytes, and proteins. Yet, existing diagnostic approaches—like tonometry or tear sampling—are often invasive, infrequent, and impractical for daily monitoring. Likewise, standard eye drop treatments suffer from poor drug retention due to blinking and drainage, limiting their therapeutic impact. Smart contact lenses have emerged as a compelling alternative. By enabling real-time sensing and controlled drug release directly on the eye, they promise to revolutionize ophthalmic care. Still, incorporating delicate microfluidic features into the curved, flexible surface of soft lenses without compromising vision or comfort remains a formidable engineering challenge. Addressing these barriers calls for continued innovation in fabrication methods and material integration.
In a comprehensive review (DOI: 10.1038/s41378-025-00909-3) published April 3, 2025, in Microsystems & Nanoengineering, researchers from the Manipal Institute of Applied Physics and Manipal University Jaipur chart the evolution of Microfluidic contact lenses (MCLs) from concept to clinical possibility. The article examines how fabrication advances—spanning soft lithography, laser patterning, and 3D-printed mold replication—are enabling lenses to measure intraocular pressure, detect biochemical markers, and deliver medication on demand. With these capabilities, contact lenses are poised to become an all-in-one platform for diagnosis, therapy, and patient comfort.
The review highlights two core applications for MCLs: sensing and treatment. For diagnostics, deformable microchannels embedded in the lens respond to pressure changes by shifting indicator fluids, enabling accurate intraocular pressure measurements—crucial for glaucoma management. Some designs have achieved sensitivities up to 708 μm/mmHg, far surpassing earlier iterations. MCLs also track tear biomarkers such as pH, glucose, lactate, and proteins via smartphone-readable colorimetric or fluorescent sensors. On the therapeutic front, drug-loaded microchambers release medication in response to external cues like magnets or electrical signals—or internal ones like pH shifts or blinking pressure. These innovations allow for on-demand delivery while maintaining the optical clarity and flexibility of the lens. Fabrication methods underpin this progress: thermoforming and PDMS replication deliver precision; 3D printing allows for personalized designs; and femtosecond lasers offer ultra-fine microchannel engraving. Though scalable production remains a challenge, these technologies are steadily converging on practical, patient-ready solutions.
"MCLs represent a convergence of vision care and advanced diagnostics," said Prof. Sajan D. George, the review's corresponding author. "Our goal is to create a single, wearable device that seamlessly combines biosensing, therapeutic delivery, and user comfort. Many of these technologies are still in development, but the progress in fabrication and materials is encouraging. We're moving closer to clinical translation."
The future of MCLs extends far beyond the ophthalmologist's office. In healthcare, they offer transformative potential for managing chronic eye conditions like glaucoma and dry eye syndrome, while also treating diseases such as diabetic retinopathy through localized, sustained drug delivery. Paired with mobile interfaces, they enable remote diagnostics and personalized treatment. Outside medicine, the integration of sensors, drug systems, and even display technologies hints at applications in sports, military, and wearable tech. To fully realize these possibilities, further advancements in scalable manufacturing, regulatory compliance, and long-term safety will be key. But one thing is certain: smart lenses are rapidly transitioning from laboratory prototypes to real-world tools in precision health.
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References
DOI
10.1038/s41378-025-00909-3
Original Source URL
https://doi.org/10.1038/s41378-025-00909-3
Funding information
M. Aravind acknowledges the T.M.A. Pai Ph.D. Fellowship from Manipal Academy of Higher Education. We gratefully acknowledge financial support from the Manipal Academy of Higher Education for the intramural grant, MRB project between S.D.G. of MAHE and D.M. of MUJ, and the FIST program of the Government of India (SR/FST/PSI-174/2012). S.D.G. acknowledges the Department of Science and Technology, Government of India (IDP/BDTD/ 20/2019) and Science and Engineering Research Board (CRG/2020/002096). Open access funding provided by Manipal Academy of Higher Education, Manipal.
About Microsystems & Nanoengineering
Microsystems & Nanoengineering is an online-only, open access international journal devoted to publishing original research results and reviews on all aspects of Micro and Nano Electro Mechanical Systems from fundamental to applied research. The journal is published by Springer Nature in partnership with the Aerospace Information Research Institute, Chinese Academy of Sciences, supported by the State Key Laboratory of Transducer Technology.