TapTechNews May 16 news, TapTechNews learned from the official website of Nanjing University that recently, a research team from Nanjing University, Jiangsu Provincial People's Hospital, and Nanjing University of Aeronautics and Astronautics has developed a contact lens with eye tracking functionality. The contact lens looks no different from regular ones, but it is based on frequency encoding strategy and spherical conformal micro/nano fabrication process. It features wireless and passive operation, lightweight and comfortable wearing, allowing for high-precision eye tracking and eye movement recognition.\n\nAccording to the official website of Nanjing University, the eye tracking contact lens consists of four wireless RF position tags distributed around the contact lens and encapsulated in medical-grade silicone rubber material. It has a curvature matching the human cornea, hydrophilic surface modification and ultra-thin thickness, making it water-moisture permeable, comfortable, and imperceptible. After wearing the contact lens, through a simple implicit calibration process, individual differences in eye movement and randomness during wearing are calibrated, enabling high-precision eye tracking based on temporal eye tracking algorithms. The eye movement angle accuracy is better than 0.5°, even smaller than the viewing angle provided by the fovea, meeting the accuracy requirements of eye tracking. The contact lens operates stably and robustly, immune to strong light and interference from projected images during eye tracking. The operating frequency of the device also avoids common electromagnetic interference sources such as cell phones and routers. In addition, the bio-compatible encapsulation of the contact lens ensures device safety, with no significant differences compared to commercial contact lenses in a 72-hour cytotoxicity test and a week-long live rabbit eye irritation test.\n\nAccording to Nanjing University, based on this contact lens, the joint team has demonstrated a variety of eye-machine interaction applications, such as eye movement text input, painting, game control, web interaction, camera control, and unmanned vehicle control. With the accurate and stable wireless eye tracking capability, diverse interaction modes, soft and comfortable structural characteristics, and bio-safe physicochemical properties of this contact lens, it is expected to be applied in human-machine interaction, eye-brain medical diagnosis and treatment, eye-brain scientific research, psychology research, and other fields.\n\nThe work titled 'Frequency-encoded eye tracking smart contact lens for human-machine interaction' was published in 'Nature Communications' [Nature Communications, 2024, 15: 3588].
