Adrien Chopin^1,2 (), Diana Rdeini^1,3, Catherine Agathos², Chiara Ciucci^1,4, Yuling Wang¹, Valérie Parmentier⁵, Denis Sheynikhovich¹, Angelo Arleo^1,5; ¹Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France, ²The Smith-Kettlewell Eye Research Institute, San Francisco, United States, ³Hôpital National de la Vision, Université Paris Cité, Paris, France, ⁴School of Advanced Study Sant’Anna, Pisa University, Pisa, Italy, ⁵Center Innovation & Technologies Europe, Essilor International SAS (EssilorLuxottica), Charenton-le-Pont, France

Introduction: Stereoscopic vision is crucial for perceiving depth. While recent research highlights its role in accurate distance estimation and object grasping, its influence in everyday tasks remains elusive, especially during aging. Methods: Sixteen younger and 16 older adults with healthy stereovision completed two daily tasks (making a cup of coffee, setting a table) within a laboratory apartment unit while hand movements were tracked. Each participant performed each task binocularly, allowing for the use of stereovision, or monocularly, preventing it. A novel eye-patching procedure equalized the visual field between monocular and binocular conditions, so that the condition difference reflected the impact of stereovision only. To assess the effect of attentional load, participants repeated each task while performing a concurrent spatial task. The order of conditions was counterbalanced in each group. Completion time and hand movement kinematics served as primary outcomes. We adjusted statistics for multiple comparisons. Results: Stereoscopic vision significantly reduced task completion time, and the reduction was greater in the older compared to the younger group (t(252) = 3.98, adjusted p = 1.8-4), with the interaction accounting for 5.2% of the variance. Attentional load increased completion time but without interacting with other factors. Participants moved their hands faster when using stereopsis (t(508) = 2.35, adjusted p = 0.029) but we found no difference in smoothness (p>0.05). Overall, completion time was influenced by translation path length, velocity, smoothness, and idle time of both hands. Conclusion: This study highlights the impact of stereoscopic vision on daily activities, particularly among older adults who benefited more in time savings in task completion. The observed enhancements imply that stereovision contributes to faster actions. Given many daily tasks rely on hand actions, age-specific interventions targeting stereovision might improve autonomy and quality of life in aging.

Acknowledgements: This research was supported by the Chair SILVERSIGHT ANR-18-CHIN-0002, by the IHU FOReSIGHT ANR-18-IAHU-01, and by the LabEx LIFESENSES (ANR-10-LABX-65).