Grosseteste had read several important works translated from Greek via Arabic, including De Speculis by Euclid (and likely also De Visu), Meteorologica and De Generatione Animalium by Aristotle, and directly from Arabic, such as Liber Canonis by Avicenna. He likely also read al-Kindi 's De Aspectibus. Drawing on these sources, Grosseteste produced important work in optics, which would be continued by Roger Bacon, who often mentioned his indebtedness to him although there is no proof that the two ever met. In De Iride Grosseteste writes: