New eye patch sensor uses light to detect eye health problems

Scientists have developed a new kind of wearable sensor that can detect signs of eye disease—without drawing blood or using expensive lab equipment. Instead, it’s a soft, non-invasive patch placed under your eye. It uses a special gel that lights up under UV light, and the only tool you need to read the result is your smartphone.

This breakthrough comes from the Institute of Solid State Physics at the Hefei Institutes of Physical Science, part of the Chinese Academy of Sciences. Professor Jiang Changlong and his research team designed the sensor using a multi-emission metal-organic framework hydrogel called Eu-Dy MOF gel. Their findings were recently published in Analytical Chemistry, a respected scientific journal.

The team’s wearable eye patch targets lysozyme, a naturally occurring protein found in your tears. Often called “the body’s own antibiotic,” lysozyme helps keep the surface of the eye free from harmful bacteria and viruses. By tracking changes in lysozyme levels, doctors can detect inflammation or infection early on. Until now, this type of testing required either invasive techniques or costly equipment.

But this new eye patch makes the process simple, quick, and comfortable.

Lysozyme isn’t just another protein—it plays a big role in your immune system, especially around your eyes. It works by breaking down the cell walls of bacteria, keeping your eyes safe from infection.

Eye infections, dry eye syndrome, and other conditions often lead to changes in the amount of lysozyme found in your tears. So, being able to track those changes in real time can help with early diagnosis and better treatment. But traditional tests are a hassle. They often involve drawing fluid from the eye with special tools or analyzing it in a lab.

This is where the new patch comes in.

Professor Jiang’s team wanted to solve this problem with something wearable and easy. They created a patch that uses fluorescence—light emitted from a substance after it absorbs energy—to detect lysozyme levels. This way, you don’t need any invasive methods. The patch simply collects tears from the skin just beneath the eye and uses color changes to show what’s happening.

Here’s how the science behind the patch works.

The key ingredient is a gel made with lanthanide ions—specifically europium (Eu³⁺) and dysprosium (Dy³⁺). These ions are embedded into a sponge-like structure known as a metal-organic framework, or MOF. This MOF gel is very sensitive to light. Thanks to a process called the “antenna effect,” it absorbs light through organic ligands and transfers that energy to the metal ions, which then give off visible fluorescent light.

This light is what allows the sensor to work.

When the patch is exposed to UV light, the gel lights up. But when lysozyme is present, it binds with the MOF material. This changes how the gel lights up. Specifically, it causes the blue fluorescence from Dy³⁺ to dim, a process known as fluorescence quenching. The effect happens because of something called static quenching and local electron transfer—fancy terms that just mean the lysozyme interacts with the gel at the molecular level, reducing its glow.

The team measured just how sensitive this change could be. Their results showed the patch could detect lysozyme at levels as low as 1.5 nanomolar—that’s 0.0000000015 moles per liter, or about 1 part per billion. This level of sensitivity makes it possible to catch even tiny changes in tear composition, which could be critical for detecting eye diseases before symptoms even appear.

One of the most exciting parts of this innovation is how easy it is to use.

Once the patch collects tears, it can be activated by shining a small UV light—something that could be built into a phone accessory. The color changes on the patch are then captured using the camera on a smartphone. A color recognition app analyzes the image and tells the user whether lysozyme levels are normal or not.

This approach avoids the need for bulky machines or medical staff. Instead, someone could wear the patch and get health information on their own, right from their phone. That opens the door for regular, real-time health checks from the comfort of home.

Not only that, but it could make eye care more available in parts of the world where medical resources are limited.

As Professor Jiang explains, “Our finding holds great potential for non-invasive detection of lysozyme in tears, promoting the widespread application of functionalized MOF fluorescent sensors in personal health monitoring, disease early warning, diagnosis, and treatment fields.”

This research shows how wearable technology is evolving far beyond fitness trackers and heart rate monitors.

By combining sensitive chemistry with digital tools like smartphone cameras and apps, health tracking is becoming more personal, more affordable, and more precise. Sensors like this one may soon help detect not just eye conditions but other diseases too—simply by monitoring natural fluids like sweat, saliva, or tears.

What makes this method stand out is the use of MOF materials. These tiny frameworks have a high surface area and excellent optical properties, which means they can be tuned to detect many different substances. By changing the structure or the ions used, similar patches could one day monitor other proteins, enzymes, or even signs of stress or fatigue.

Because the patch uses fluorescence instead of electrical signals, it doesn’t need a power source, wires, or batteries. That makes it safer and easier to wear, especially near sensitive areas like the eyes.

More importantly, this type of wearable can be made in a lab using low-cost materials, which could lower the price if the patch ever becomes widely available.

The patch’s ability to sense real-time changes in a person’s biochemistry offers a glimpse into the future of personalized health monitoring. It might become possible to detect illness before symptoms show up, alert users to flare-ups of chronic conditions, or even help tailor treatments on a day-by-day basis.

And the best part? It all fits in your pocket.

Note: The article above provided above by The Brighter Side of News.

Like these kind of feel good stories? Get The Brighter Side of News' newsletter.