One of the most famous discoveries Ludwig Schuba made when preparing his catalogue of medical and quadrivial codices kept in Bibliotheca Palatina is the identification of the hand of Reimbotus de Castro (fl. 1350s-1380s), personal physician of emperor Charles IV, as well as a group of codices from his personal library, many of them including Reimbot?s autographs. This paper restricts its focus to two texts on science of optics (perspectiva) written by Reimbot?s hand and included in Pal. lat. 1380. Closer reading of these texts, hitherto unnoticed by historians of medieval science, reveals they are inspired by the famous 13th-century compendium of optical knowledge - Perspectiva communis by John Peckham which was widely read among medieval scholars (more than 60 manuscripts are extant today). Once the contents of these text are considered and compared with Peckham?s textbook, it may be suggested that the first text is Reimbot?s reportatio of lectures on Peckham?s text, whereas the second text is an optical treatise inspired by Peckham rather loosely (it borrows many propositions from Peckham but reworks the structure of presentation of optical knowledge significantly). It is surmised both texts originated in Paris university milieu, probably in the 1360s when Reimbot studied there. Finally, the aim of these texts and their intended audience are discussed, as well as why a royal physician might be interested in them.