These smart lenses are similar to regular contact lenses, butthey contain technology that allows eye health monitoring. (Pormezz/Shutterstock)
In a nutshell
- A new smart contact lens can monitor both eye pressure and eye movement, even while your eyes are closed, providing critical data that current open-eye devices miss, especially during sleep.
- In early tests, the lens accurately detected small changes in intraocular pressure and tracked eye movements with over 97% accuracy, using wireless signals sent to special eyeglass frames.
- While the results are promising, the technology is still in early stages, with limited human testing and unproven long-term durability in real-world use.
CHENGDU, China — Most glaucoma damage happens when patients aren’t looking — literally. Since current eye pressure tests only work when your eyes are open and you’re sitting in a doctor’s office, physicians miss the crucial nighttime pressure spikes that cause irreversible vision loss. A new smart contact lens just changed that equation entirely.
Scientists from the University of Electronic Science and Technology of China have developed a smart contact lens that can simultaneously measure intraocular pressure, the fluid pressure inside your eye, and track eye movements. The lens wirelessly transmits data to sensors built into eyeglass frames.
The lens works even when your eyes are closed, solving a major limitation of current eye monitoring technology. Most existing devices require your eyes to be open, which means doctors miss nighttime monitoring when many eye problems actually worsen.
According to the research published in Microsystems & Nanoengineering, nocturnal intraocular pressure exhibits a significant circadian rhythm. It typically peaks in the early morning hours before the end of sleep, with levels 3-4 mmHg higher than daytime readings. For people with glaucoma, a leading cause of blindness, this nighttime pressure spike can cause irreversible damage while patients sleep.
How the Lenses Work
Eye doctors can only get a snapshot of your eye health in an eye exam. (Drazen Zigic/Shutterstock)
The contact lens appears similar to a regular-colored contact but contains sophisticated monitoring technology. At its core are two main systems: electromagnetic sensors made of spiral copper coils for pressure detection, and magnetic particles embedded in a flexible material for eye movement tracking.
When eye pressure changes, it slightly deforms the contact lens. This deformation alters the electromagnetic properties of the copper coils, which can be detected wirelessly by sensors in the eyeglass frames. The magnetic particles track eye movements by detecting changes in magnetic fields as the eye moves in different directions.
The lens measures approximately 195 micrometers thick, falling within the range of commercially available contact lenses, and is designed to withstand up to 20% stretching without structural damage.
Researchers conducted testing using artificial eye models, rabbit studies, and human volunteer trials. In rabbit testing, the system demonstrated the ability to detect pressure changes as small as 1 mmHg, with sensitivity measurements of 0.22 MHz per mmHg for open eyes and 0.758 MHz per mmHg for closed eyes.
The results for eye movement tracking showed high accuracy rates. In laboratory conditions with human volunteers, the system achieved 99.375% accuracy with eyes open and 97.5% with eyes closed. In real-world testing scenarios, accuracy remained high at 97.5% for open eyes and 97.25% for closed eyes.
The human trials involved two volunteers, ages 22 and 23, who wore the smart contact lens along with the monitoring eyeglass frames. The system successfully tracked eye movements in eight directions while simultaneously monitoring eye pressure.
Safety and Biocompatibility
Safety testing included having rabbits wear the lenses for one week, followed by microscopic tissue examination using specialized tissue staining. Results showed no signs of inflammation or tissue damage. Tests on human eye cells showed that more than 90% of the cells stayed healthy after being exposed to the lens materials for 72 hours.
Design and characterization of the stretchable BCL. (Credit: Microsystems & Nanoengineering)
Computer simulations showed that even when the lens was put under a lot of pressure, its parts held up well and didn’t come close to breaking, proving the design is strong and durable.
The device was only tested on two people for short periods of time, so scientists don’t yet know how safe or effective it is to wear for longer than a week. Most of the testing was also done in labs, not in everyday situations.
The system also depends on wearing special eyeglass frames to collect data, which could make it harder for people to use in real life. And it’s still unclear how well the device would hold up with regular use over months.
Still, the researchers believe this smart lens could eventually be used for more than just glaucoma. It might help monitor other eye diseases, track recovery after eye surgery, or even catch early signs of conditions like diabetes that affect the eyes.
One of the biggest threats to your vision happens while you’re unconscious. This smart contact lens finally gives doctors and patients the round-the-clock surveillance they need to fight back against the leading cause of irreversible blindness worldwide.
Paper Summary
Methodology
Researchers developed a multi-layered smart contact lens using spiral copper coils for pressure sensing and magnetic particles for eye movement tracking. Testing occurred in three phases: artificial eye models with varying curvatures, live rabbit studies with controlled pressure changes, and human volunteer trials. The contact lens transmitted data wirelessly to sensors embedded in eyeglass frames, which processed information using deep learning algorithms for eye movement recognition.
Results
The smart contact lens achieved 1 mmHg pressure detection sensitivity and eye movement tracking accuracy exceeding 97% in both open and closed-eye conditions. Rabbit studies demonstrated linear responses to pressure changes from 720-728 mmHg. Human trials with two volunteers (ages 22-23) showed successful real-time monitoring of both eye pressure and movements across eight directional patterns, outperforming existing commercial eye tracking systems.
Limitations
The study involved only two human participants and relatively short testing periods. Long-term effects of extended wear beyond one week weren’t evaluated. Research was primarily conducted in controlled laboratory settings, and real-world durability over months of daily use remains unproven. The system requires specialized eyeglass frames for data collection, which may limit practical adoption.
Funding and Disclosures
Research was supported by multiple Chinese funding sources including the National Natural Science Foundation of China, Science and Technology Major Project of Tibetan Autonomous Region, Science and Technology Department of Sichuan Province, and Medico-Engineering Cooperation Funds. Authors declared no competing interests.
Publication Information
The study “Closed-eye intraocular pressure and eye movement monitoring via a stretchable bimodal contact lens” was published in Microsystems & Nanoengineering in 2025. Research was conducted by Xingyi Gan and colleagues from the University of Electronic Science and Technology of China and affiliated institutions. The paper was received December 26, 2024, revised March 17, 2025, and accepted April 8, 2025.
