On August 20, a research team from the Korea Advanced Institute of Science and Technology (KAIST) announced that they had successfully integrated an OLED light source into an ultra-thin flexible contact lens, creating a new generation of ophthalmic diagnostic technology.
Image source: KAIST
According to reports, this technological achievement is expected to be applied in a variety of fields, including myopia treatment, ocular biosignal analysis, AR visual information transmission, and light-based neural stimulation.
In their paper published in *ACS Nano*, the team pointed out that ocular optoelectronic systems can meet a variety of medical needs, including monitoring physiological signals related to vision or other diseases. This research introduced a wearable light source, combining an ultra-thin OLED with a contact lens.
This new type of contact lens can be used for clinical electroretinography (ERG) testing, which measures the electrical responses of different cell types in the retina. Traditional ERG diagnosis usually requires a complex setup of equipment, requiring the patient to remain still with their eyes open in a dark environment while their eyes are illuminated by an external light source and imaging device.
To overcome these limitations, the KAIST team integrated an ultra-thin flexible OLED with a thickness of only about 12.5 micrometers into the contact lens electrode and configured it with a wireless power receiving antenna and control chip, thus completing a system that can operate independently.
The research team stated that, unlike traditional ERG which requires a dark environment, their study allows patients to comfortably complete the test even with their eyes closed.
Furthermore, the research team pointed out that most current smart contact lens light sources use inorganic LEDs, which results in rigid devices and excessive heat generation, thus limiting the usable light intensity. In contrast, OLEDs are surface light sources that can induce retinal responses even under low-brightness conditions.
In the research experiments, the device developed by the research team still managed to induce a stable ERG signal at a relatively low brightness of only 126 nits, and its diagnostic performance was comparable to that of existing commercial light sources. Animal experiments also confirmed that rabbits wearing OLED contact lenses maintained an eye surface temperature below 27°C, avoiding corneal thermal damage.
The research team also explained that the new contact lens is powered by wireless transmission at a resonant frequency of 433 MHz. They further enhanced the ease of use for patients by embedding the wireless controller into a sleep mask that connects to a smartphone. (Compiled by TrendForce Display)
