Ultra-sensitive real-time monitoring of intraocular pressure with an integrated smart contact lens using parity-time symmetry wireless technology

In recent years, smart contact lenses as a type of wearable device have attracted significant attention in health monitoring and disease detection. In this study, we combine a resistive sensor based on a cracked PEDOT: PSS structure with a 70 MHz double-loop gold antenna, enabling high-precision and continuous measurement of intraocular pressure (IOP). By comprehensively optimizing the sensor design, device structure, and wireless detection system, we achieved a sensitivity of 47.31 Ω/mmHg—approximately 15 times higher than conventional approach, corresponding to a resistance change 183 times larger. Both in vitro wireless IOP measurements of a porcine eye and in vivo wireless IOP measurements of rabbit eyes altered by microbead injection, using a commercial tonometer and a fabricated sensor lens, showed a strong correlation with R² values of 93% and 97%, respectively. These findings highlight the platform’s potential for long-term, non-invasive IOP monitoring, thus making a significant contribution to early diagnosis and treatment of glaucoma.