When, in 1572, Friedrich Risner published the very first printed edition of the Latin translation of Ibn al-Haytham's Book of Optics (Kitāb al-Manāẓir), he chose to publish it together with another treatise, written in Europe, but largely based on Ibn al-Haytham's work: Witelo's Perpectiva, composed around 1270. Risner titled this collection of works Opticae thesaurus (‘Treasure of Optics’), a real treasure indeed, as it remained, for more than 400 years, the only printed edition available of Kitāb al-Manāẓir (translated into Latin as De aspectibus, with the name of the author rendered as Alhacen or Alhazen). It was not until recently that critical editions of the text were published in Arabic (by Sabra) and in Latin (by Smith and by me), alongside English and French translations.