Díaz-Cano Ocaña, AntonioGonzález Gascón, FranciscoSánchez Soto, Luis Lorenzo2023-06-222023-06-222022-032073-899410.3390/sym14030478https://hdl.handle.net/20.500.14352/71401© 2022 by the authors. This research was funded by Ministerio de Ciencia, Innovación y Universidades Grant number PGC2018-099183-B-I00.We investigate the behavior of the solutions of the ray equation in isotropic media. We discuss local and global transversals and wavefronts and give examples of rays without wavefronts.engAtribución 3.0 Españahttps://creativecommons.org/licenses/by/3.0/es/journal articlehttps://doi.org/10.3390/sym14030478https://www.mdpi.comopen access535Geometrical opticsRay equationEikonal equationWavefrontsÓptica (Física)2209.19 Óptica Física