Domestic researchers have developed the next-generation ophthalmic diagnostic technology powered by wireless operation that replaces conventional retinal diagnostic methods with 'ultra-thin organic light-emitting diode (OLED)' technology. It is expected to be applicable in various fields such as myopia treatment, analysis of ocular bio-signals, augmented reality (AR) visual transmission, and light-based neural stimulation in the future.
A research team led by Professor Yoo Seung-hyup from the Korea Advanced Institute of Science and Technology (KAIST), along with Professor Woo Se-jun from Seoul National University Bundang Hospital, Professor Han Se-gwang from Pohang University of Science and Technology (POSTECH), PHI Biomed, and the Electronics and Telecommunications Research Institute (ETRI), announced on the 12th that they have developed the world's first wireless contact lens-based wearable retinal diagnostic platform using OLED technology.
Electroretinography (ERG) is an ophthalmic diagnostic method that measures whether the retinal function is operating normally and is widely used for the diagnosis of hereditary retinal diseases and assessing retinal function decline. Conventional ERG requires patients to keep their eyes open and remain still in a dark room to conduct tests with fixed equipment. This posed limitations not only in spatial constraints but also in terms of patient fatigue and cooperation.
To overcome such limitations, the research team integrated an ultra-thin flexible OLED, which is 6 to 8 times thinner than a human hair, into the ERG contact lens electrodes and incorporated a wireless power receiving antenna and control chip to complete a system that can operate independently. Generally, inorganic LEDs used in smart contact lenses emit light too strongly, which can cause heat damage, whereas OLEDs illuminate in a wide and uniform manner.
Results from animal experiments showed that the surface temperature of the eyes of rabbits wearing OLED contact lenses remained below 27 degrees Celsius, preventing heat-induced damage to the cornea covering the eye. The performance of light emission is maintained even in high-temperature and humid environments, proving it could serve as an effective and stable ERG testing tool in actual clinical settings.
The technology developed this time allows for retinal potential testing to be conducted simply by wearing the lens, significantly simplifying the existing complex ophthalmic diagnostic methods without the need for large special light source installations.
Professor Yoo Seung-hyup noted, "The integration of the flexibility and diffused light characteristics of ultra-thin OLED into contact lenses is a world-first attempt, and this research will help expand existing smart contact lens technology into a light-based optical diagnosis and treatment platform," adding, "I hope it can contribute to the expansion of digital healthcare technology."
The research results were published online in the American Chemical Society Nano (ACS Nano) in May.
References
ACS Nano (2025), DOI: https://doi.org/10.1021/acsnano.4c18563