An inconspicuous and modular head-mounted eye tracker

State of the art head mounted eye trackers employ glasses like frames, making their usage uncomfortable or even impossible for prescription eyewear users. Nonetheless, these users represent a notable portion of the population (e.g. the Prevent Blindness America organization reports that about half of the USA population use corrective eyewear for refractive errors alone). Thus, making eye tracking accessible for eyewear users is paramount to not only improve usability, but is also key for the ecological validity of eye tracking studies. In this work, we report on a novel approach for eye tracker design in the form of a modular and inconspicuous device that can be easily attached to glasses; for users without glasses, we also provide a 3D printable frame blueprint. Our prototypes include both low cost Commerical Out of The Shelf (COTS) and more expensive Original Equipment manufacturer (OEM) cameras, with sampling rates ranging between 30 and 120 fps and multiple pixel resolutions.