My project aims at exploring the communication of knowledge in the field of visual phenomena in the first half of the seventeenth century and, more precisely, the exchanges between Descartes, Gassendi, and Mersenne, three major figures in the scientific community at that time. Optics is the field by excellence for the study of scientific communication in the 17th century because many important discoveries were made and because optical phenomena were not always accessible to everyone at the same time. Exchanges, mainly through letters, therefore became crucial for the rise of modern science and the evolution of disciplinary boundaries. They testify to the possibility and necessity for contextual observations to reach a higher level of generality, so they can be shared and assimilated within different epistemological and scientific contexts. The systematic exploration of the effective scientific network constituted by those three figures will allow me to study how their respective philosophies and epistemologies impacted (and were impacted by) the interpretation of optical data. I therefore intend to shed new light on the importance of scientific communication in that period and, in so doing, to provide a new insight on the early modern natural philosopher as regards his approach to experience.