A team of Korean researchers has created the world’s first wireless contact lens that can test how well your retina works—potentially replacing the bulky, darkroom-based equipment used in clinics today.
The technology is based on electroretinography (ERG), a standard test that measures whether the retina—the light-sensitive layer at the back of the eye—is working properly.
ERG is often used to diagnose inherited eye diseases or check for vision loss.
At the moment, ERG is usually done with large machines in a dark room, requiring patients to sit still with their eyes open for a long time. This can be uncomfortable and tiring.
The new device, developed by scientists from KAIST, Seoul National University Bundang Hospital, POSTECH, PHI Biomed Co., and the Electronics and Telecommunications Research Institute, changes that.
By building an ultra-thin organic light-emitting diode (OLED) into a soft contact lens, the team has made it possible to perform ERG simply by wearing the lens. No large machines. No darkroom.
The OLED is incredibly thin—just 12.5 micrometers thick, or about 6–8 times thinner than a human hair. It’s flexible enough to fit comfortably in a contact lens and works together with a built-in electrode to stimulate the retina.
The lens also includes a wireless antenna and control chip, so it can run without being plugged into anything.
Power is sent wirelessly to the lens using a 433 MHz frequency, which allows for stable operation. The researchers even built a wireless controller into a sleep mask, which can connect to a smartphone. This makes the whole setup more portable and user-friendly.
Most previous smart contact lenses for eye illumination have used tiny inorganic LEDs.
These emit light from a small point, which can cause heat buildup and limit how bright they can be. OLEDs, on the other hand, spread the light more evenly and can trigger retinal responses at lower brightness levels.
In tests, the OLED lens successfully produced clear ERG results at just 126 nits of brightness—matching the quality of commercial ERG devices.
Animal studies showed that the lens stayed cool, keeping eye surface temperatures below 27°C, which is safe for the cornea. The OLED’s performance also held up in humid conditions, suggesting it could work well in real-world clinical environments.
Professor Seunghyup Yoo of KAIST, who led the project, said this is the first time ultrathin OLEDs have been integrated into a contact lens for this purpose.
He believes the technology could lead to new types of “smart” contact lenses for eye health diagnostics, light-based therapies, and even augmented reality.
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Source: KAIST.
Wireless operation of the OLED contact lens. Credit: KAIST.
