Wearable transparent OLED glasses for cognitive stimulation: Enhancing brain connectivity through gamma entrainment.

Gamma wave entrainment is a promising approach for improving cognitive function, particularly in the early stages of Alzheimer's disease. However, for everyday treatment, a light source system that maintains visibility while delivering effective stimulation is essential for patient comfort and practicality. To address this need, we developed organic light-emitting diode (OLED) glasses with optimized large-area transparent OLEDs for gamma wave entrainment. The optimization involved all layers of the device, including encapsulation, to achieve high luminous transmittance (75%), uniformity (over 90%), and electrical performance, ensuring suitability for wearable applications. Under real-world conditions (see-through visibility and ambient light present), the transparent OLED glasses successfully induced gamma rhythm entrainment, enhancing brain connectivity between the occipital and frontal regions. They also notably reduced visual discomfort and showed a trend of enhanced connectivity compared to nontransparent OLEDs. These results highlight the potential of this noninvasive wearable technology for early cognitive intervention, providing comfortable therapeutic light stimulation.