/usr/share/optgeo/exemples/Aberrations_Stigmatisme_Approche/Lentille/ is in optgeo 2.21-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/optgeo/exemples/Aberrations_Stigmatisme_Approche/Lentille/aberration_spherique.opt
/usr/share/optgeo/exemples/Aberrations_Stigmatisme_Approche/Lentille/aberration_spherique.txt
/usr/share/optgeo/exemples/Aberrations_Stigmatisme_Approche/Lentille/aberrations_objet_infini_hors_axe.opt
/usr/share/optgeo/exemples/Aberrations_Stigmatisme_Approche/Lentille/aberrations_objet_infini_hors_axe.txt
/usr/share/optgeo/exemples/Aberrations_Stigmatisme_Approche/Lentille/aberrations_objet_infini_sur_axe.opt
/usr/share/optgeo/exemples/Aberrations_Stigmatisme_Approche/Lentille/aberrations_objet_infini_sur_axe.txt
/usr/share/optgeo/exemples/Aberrations_Stigmatisme_Approche/Lentille/foyer_image.opt
/usr/share/optgeo/exemples/Aberrations_Stigmatisme_Approche/Lentille/foyer_image.txt
/usr/share/optgeo/exemples/Aberrations_Stigmatisme_Approche/Lentille/reduction_aberration_spherique.opt
/usr/share/optgeo/exemples/Aberrations_Stigmatisme_Approche/Lentille/reduction_aberration_spherique.txt