sentences:  For a few years he studied with Frédéric Jules Sichel, and in 1839, he started his own practice.Deval is largely remembered for his written works on ophthalmic medicine, in particular, the 1844 ""Traité de Chirurgie Oculaire"", which was only the second French work devoted exclusively to eye surgery.This book was important because it helped introduce German and Austrian ophthalmic practices into French medicine.