The aim of the research is to investigate the transformation of the perception process through mathematics education, by an example of scanning the Cartesian coordinate system in order to locate a target point. We compared participants with different competence in mathematics. Historically, motion along axes appeared as a specific "theoretical" action that constituted the Cartesian coordinate system. We detected this specificity as a dominance of vertical and horizontal saccades of eye movements in perception processes of all groups of participants. Experts-novices differences dealt with an ability of experts to use additional essential information and to discard unnecessary data. Furthermore, a lot of evidences of shortening of the perception actions from novices to experts are presented. [For the complete proceedings, see ED597799.]