XPANCEO unveils passive eye tracking using smart contact lenses

XPANCEO, a deep-tech company developing smart contact lens, has unveiled a passive eye-tracking system that achieves industry-level measurement precision using standard cameras. The system employs microscopic patterns embedded in contact lenses that enable high-accuracy passive gaze tracking without requiring active electronics or dedicated power sources. 

This technology allows contact lenses to function as optical markers that can be read by existing cameras in laptops, vehicle dashboards, mobile devices, and helmet-mounted systems. The system uses two ultra-thin optical gratings that create interference patterns that shift as the eye rotates. As the eye rotates and the viewing angle changes, the gratings (separated by a microscopic gap) shift relative to each other, similar to how layers in a pop-up book change position when tilted. This causes the so-called moiré patterns to undergo a measurable transformation.

The tracking module measures 2.5 × 2.5 millimeters and is encapsulated in a biocompatible silicone elastomer, compatible with conventional contact lens manufacturing processes. 

Current eye-tracking technologies mostly rely on external systems and work by shining infrared light onto the eye and using cameras to capture the reflection patterns from the cornea and sometimes the crystalline lens. Computer vision algorithms then analyze these images by calculating corresponding gaze direction and processing the relative positions of multiple glints and the shape and position of the pupil.

This continuous cycle of illumination, imaging, and analysis happens dozens of times per second. These systems drain batteries relatively quickly and experience reduced performance in challenging lighting conditions, including well-lit environments where infrared signals compete with the ambient light. 

The new pattern-based technology offers two key advantages. First, the simplified setup eliminates the need for infrared illumination and works reliably in well-lit environments, reducing hardware complexity and power consumption. Second, it enables universal deployment. Since cameras are already embedded in everyday devices and environments, the passive tracking system functions across multiple contexts without requiring dedicated infrastructure. 

"This moiré pattern approach provides accurate eye orientation measurement using optical geometry without adding complexity or energy requirements to the lens," said Dr. Valentyn Volkov, Founder and CTO of XPANCEO. "The technology extends the potential applications of contact lens platforms, particularly in environments where users are already interfacing with camera-equipped devices." 

This unique 0.3- degree precision without the need for restrictive clinical hardware makes the system a promising solution to detect subtle eye movements in clinical applications, including the study of patterns associated with neurological conditions. Such high-fidelity eye-tracking is increasingly recognized as a vital biomarker for the early diagnosis of neurodegenerative conditions, including Parkinson's and Alzheimer's diseases, with recent research establishing specific protocols for diagnosis. 

Furthermore, the system's robustness makes it highly adaptable to extreme and high-stakes environments. In automotive, aerospace, or industrial settings, where users often wear helmets with embedded cameras, the continuous analysis of saccadic velocity and micro-fixations goes far beyond standard fatigue monitoring. It enables the real-time detection of severe central nervous system fatigue, cognitive impairment, or intoxication, ensuring that operators are fully capable of performing their duties. 

This technology expands the applications of smart contact lenses without increasing the system complexity. The research has been published in Advanced Functional Materials.