WP 3.2: Plasticity of the accommodative system and eye-hand coordination

Loss of accommodation due to presbyopia can impair visually guided actions such as reaching, grasping, and object manipulation. This work package will quantify how changes in accommodation affect eye–hand coordination during natural tasks and examines whether training or targeted correction can improve performance.

Within the project, we have established and validated a synchronized measurement framework that combines mobile eye tracking with high‑speed motion capture, by integrating a mobile head-mounted eye-tracking device with an infrared 3D motion capture system. Combining these two modalities to enable synchronized recording of gaze and upper-limb kinematics is challenging because they operate in separate coordinate systems and on independent clocks. To address this, we have developed and evaluated a dual synchronization pipeline including robust temporal and spatial registration between the two systems. Both systems are now in a shared spatial reference frame, and the completed framework will yield precise spatiotemporal registration of fixation strategy, saccade timing, reach onset, trajectory, and endpoint accuracy under controlled visual demands. The next stage of the project will investigate how accommodation loss due to presbyopia affects the visuomotor control and the speed and precision between gaze and hand movements.