Abstract
PURPOSE: To test on humans an eye tracker based on the use of a contact lens with active infrared sources and to evaluate whether this system can track the eye behind the eyelid. METHODS: The system is made up of a scleral contact lens embedding two vertical cavity self-emitting lasers (VCSELs) remotely driven by eyewear comprised of electronics and cameras. Tests on humans were carried out on five subjects to assess performance and to determine whether the VCSEL spot could be detected behind the eyelid. RESULTS: The lens was worn and used without difficulty. The device allowed accurate tracking of the eye (0.83° ± 0.59°), and the VCSELs can be detected behind closed eyelids. CONCLUSIONS: These results confirm those previously obtained in terms of tracking and demonstrate that the device can be used safely to monitor eye movements even when the eyelids are closed. TRANSLATIONAL RELEVANCE: The VCSELs could be useful for a variety of applications to reduce data missed due to blinks, particularly with regard to interactive systems, fundamental studies on closed eye movements, or finding ways to improve clinical diagnostic precision for disorders of consciousness.