Much of our current understanding of brain-based visual processing is derived from studies involving immobilised animals. However, in reallife scenarios, visual perception is intrinsically linked with the movements of the eyes, head, and body. To gain amore comprehensive understanding of visual processing under these conditions, studying eye movement in freely moving subjects, such as mice is crucial. Our research is dedicated (i) to developing innovative hardware and software solutions to facilitate this advanced tracking and analysis and (ii) employing these techniques to study freely moving visually guided behaviours.AIM1: Establish hardware/software for tracking the eye in freely moving conditions: I developed a head-mounted system using a compact, high-resolution miniature endoscopic camera to record the eye. I designed a comfortable, secure camera holder to ensure accurate positioning during surgical implantation. This will enable us to track the mouse's eye positions and gaze direction.AIM2: Establish a method to determine light patterns projected on the mouse eye:I've utilised advanced rendering software, specifically Blender and Keyshot, to recreate a 3D model of our experimental mouse behavioural arena. This model has been integrated with 3D tracking technology to monitor mouse eye movements. By applying ray tracing techniques, I've been able to simulate the reflections on a mouse's cornea as it interacts with this 3D environment. Currently, I'm working on modelling the mouse's eye to understand better the images projected onto its retina. This innovative approach is poised to offer groundbreaking insights into how mice perceive their surroundings and interact with them.