A smart contact lens that can detect changes in intraocular pressure in glaucoma patients and even deliver treatment has been developed. Made only of soft polymer material like conventional soft lenses, without metal sensors or electronic circuits, it offers excellent comfort and does not obstruct vision. If the efficacy proven in animal studies is also confirmed in human clinical trials, it is expected to open a new path for glaucoma treatment.
A research team led by Professor Yangzhi Zhu at the Terasaki Institute for Biomedical Innovation in the United States said in the international journal Science Translational Medicine on the 8th (local time) that it "developed a smart contact lens that measures intraocular pressure and automatically releases therapeutics, and verified its efficacy and safety in animal experiments." The team said that, by using a simple physical phenomenon in which diagnostic reagents and therapeutics move according to changes in intraocular pressure, the lens does not require metal sensors, electronic circuits, or batteries like existing smart contact lenses.
Glaucoma is a disease in which fluid does not drain properly from the eye and accumulates, raising intraocular pressure. It causes severe pain and optic nerve damage, and in severe cases can lead to vision loss. Currently, 70 million people worldwide have glaucoma, and with accelerating population aging, the number is expected to reach 134 million by 2040. Glaucoma is difficult to cure completely, but early diagnosis and treatment can slow vision loss and maintain quality of life. Countries around the world are engaged in fierce competition to commercialize smart contact lenses that track intraocular pressure in real time and automatically release drugs.
◇ Equipped with diagnostic reagent and drug reservoirs
The Terasaki Institute, a nonprofit research organization in Los Angeles, developed the contact lens as a diagnostic and therapeutic medical device. With exams every 6 to 12 months as is done now, it is difficult to accurately check the intraocular pressure of glaucoma patients whose readings fluctuate greatly. Because contact lenses are worn continuously, they can measure intraocular pressure in real time. Above all, the research team said this smart contact lens is made only of polymer material like conventional soft lenses, offering the same wearing comfort.
The smart contact lens has a structure in which reservoirs containing diagnostic reagents and therapeutics are placed between the outer and inner protective layers. When intraocular pressure rises, the cornea expands. Then the reagent reservoir is compressed and moves along a serpentine microchannel. The distance the reagent travels is proportional to the pressure level. When the patient takes a photo of the eye with a smartphone camera, artificial intelligence (AI) provides an accurate intraocular pressure reading.
The reservoirs use a silk-based sponge structure that holds a large amount of drug while supporting the microchannels so they do not collapse, improving the accuracy of pressure measurement. As intraocular pressure rises, the therapeutic reservoir is compressed at the same time. When the pressure exceeds a set threshold, a pathway opens and a drug that lowers intraocular pressure is released. The drug is automatically released even without a signal from an external device.
Two drugs, timolol and brimonidine, are loaded separately to enable stepwise treatment according to the pressure level. The team fitted the lenses onto the eyes of live rabbits and confirmed stable tracking of intraocular pressure and automatic drug release when the set threshold was exceeded. Zhu said, "The technology we developed can be directly applied to commercially available soft lenses and could be used to diagnose and treat various ophthalmic diseases." The study also involved Professor Lee Tae-woo of the Department of Materials Science and Engineering at Seoul National University and researchers from China, Hong Kong, the United Kingdom, and Canada.
◇ Korean glaucoma smart lens to begin clinical trials this year
Smart contact lenses for diagnosing eye diseases have been under development since the 2010s. Google in the United States worked with Swiss drugmaker Novartis to develop contact lenses that measure blood glucose in people with diabetes, and contact lenses for glaucoma patients developed by Swiss company Sensimed received U.S. marketing approval in 2016. Those lenses measure only changes in intraocular pressure. Going forward, smart contact lenses that deliver drugs as well as diagnosis are expected to be commercialized. Korean corporations are at the forefront.
The Korea Medical Device Development Fund, which oversees cross-ministerial full-cycle projects, selected and announced the "Top 10 flagship projects for 2025" in Feb. last year. One of them is PHI BIOMED's smart contact lens for glaucoma diagnosis and treatment. PHI BIOMED is a company founded in 2014 by Professor Han Se-gwang of the Department of Materials Science and Engineering at Pohang University of Science and Technology POSTECH. PHI BIOMED used gold nanowires for glaucoma diagnosis.
When intraocular pressure rises, the curvature of the cornea changes minutely, altering the shape of the nanowires and changing their electrical resistance. By measuring this resistance wirelessly, changes in intraocular pressure can be detected in real time. When intraocular pressure increases, the contact lens delivers timolol, a therapeutic agent, to the eye.
Han said the gold nanowire sensor outperforms the metal ring sensor used in existing smart contact lenses in both sensitivity and transparency. The metal ring embedded in existing smart contact lenses is visible to the naked eye, but the nanowire sensor is invisible, making the lens nearly transparent. Han previously published related findings in Nature Communications in 2022, drawing global attention. Animal experiments have already been completed, and human clinical trials will begin this year, with a plan to commercialize as early as 2027.
◇ Japanese team boosts sensor sensitivity 183-fold
Competition to improve the sensitivity of smart contact lens sensors is also fierce. A research team led by Professor Takeo Miyake at Waseda University in Japan announced in Jan. that it had developed a smart contact lens with intraocular pressure measurement sensitivity 183 times higher than previous studies. As with Professor Han Se-gwang's approach, the principle is to wirelessly detect changes in the electrical resistance of a metal sensor when the cornea expands slightly as intraocular pressure rises.
The lens sensor and the external reader exchange energy via near-field magnetic resonance. The team used a state-of-the-art technique called "parity-time (PT) symmetry" to boost sensor sensitivity. The Waseda team made the energy-loss circuit of the lens sensor and the gain circuit of the reader mirror each other symmetrically. Like synchronizing the rhythm between a person on a swing and a person pushing, the technique greatly amplifies tiny changes by perfectly matching the energy exchange.
Thanks to this, the team said even minute changes can be detected immediately. If an ordinary sensor is like trying to nudge a ball resting on a very heavy boulder, a PT-symmetric sensor is like a ball precariously balanced on the tip of a sharp pencil. Even a light breeze will knock the ball over. In other words, it can detect tiny changes in intraocular pressure right away. The Waseda team demonstrated performance by mounting the lenses on rabbit eyes.
References
Science Translational Medicine (2026), DOI: https://doi.org/10.1126/scitranslmed.ads9541
npj Flexible Electronics (2026), DOI: https://doi.org/10.1038/s41528-025-00507-3
Nature Communications (2022), DOI: https://doi.org/10.1038/s41467-022-34597-8