KAIST develops wireless OLED contact lens for retinal diagnostics

Electroretinography (ERG) is widely used to evaluate whether the retina functions normally, supporting diagnoses of hereditary retinal diseases or declining visual performance. Traditionally, the procedure requires a stationary Ganzfeld device in a darkroom setting, which often causes discomfort for patients. 

Now, a joint research team led by KAIST, in collaboration with Seoul National University Bundang Hospital, POSTECH, PHI Biomed Co., and the Electronics and Telecommunications Research Institute (ETRI), has presented a contact lens–based wireless ERG platform using organic light-emitting diodes (OLEDs). 

The research team embedded an ultrathin flexible OLED, only 12.5 micrometer thick, into a contact lens electrode. This setup integrates: 

• A wireless power receiving antenna 

• A control chip for autonomous operation 

• 433 MHz resonant frequency power transmission for stable communication 

A wireless controller embedded in a sleep mask and linked to a smartphone was also tested, showing practical usability in real-world applications. 

Most previous smart contact lenses used inorganic LEDs, which emit light from a single point and risk overheating. OLEDs, by contrast, act as diffusive areal light sources, reducing heat while ensuring consistent illumination. 

Key findings include: 

• Stable ERG signals at low luminance (126 nits), equivalent to results from commercial light sources 

• Temperature safety: animal tests confirmed eye surface temperatures remained below 27°C, avoiding heat damage 

• Durability in humid conditions, ensuring usability in clinical environments 

Professor Seunghyup Yoo from KAIST emphasized: “integrating the flexibility and diffusive light characteristics of ultrathin OLEDs into a contact lens is a world-first attempt,” and that “this research can help expand smart contact lens technology into on-eye optical diagnostic and phototherapeutic platforms, contributing to the advancement of digital healthcare technology.” 

MEDICA-tradefair.com; Source: KAIST (Korea Advanced Institute of Science and Technology)