Poster Session I: LissEYEjous Tracker - precise fundus tracking device based on ultrafast Lissajous scanning.

Retinal eye tracking has emerged as a promising alternative to conventional video-based trackers, offering direct access to retinal coordinates with refined spatial and temporal resolutions. These attributes make them attractive for applications ranging from image stabilization in advanced ophthalmic imaging to identifying biomarkers of neurological or ophthalmic disorders that affect eye motility. Existing retinal tracking method however face challenges related to reliance on reference frames and non-uniform sampling either in space or time. In this work we present a new approach for retinal tracking, which is based on imaging small retinal patches (~1.5-3°) using self-repeating Lissajous scanning patterns. Pattern repetition rates close to 4kHz are achieved with an optical design that employs two MEMS microscanners with closely matching resonant frequencies, working in mutually perpendicular dimensions. Several examples of fundus images acquired with different Lissajous patterns are presented. Based on this, eye trajectories may be extracted. Future works will further investigate tracking resolution and dependence on Lissajous pattern spatial density and repetition rate.