[History of strabismology: I--strabismology in the countries of Western Europe]

Part I contains a description of treating amblyopia and strabismus since the XVIth century. The author deals with the gradual development of ophthalmology with regard to the modes of investigations, which automatically influenced the evolution of strabology. The description covers the development of German, English and French strabology concerning the treatment of binocular vision by means of synoptophore, and also the treatment of amblyopia by Bangerter and Cüppers's method, as well as penalization. The author discusses the significance of evaluating the binolcular vision state by tests in free space, besides the synoptophore ones. At the end the author reaches the conclusion that, over such a long period of time, there have been trends of resorting to certain methods, e.g. Bangerter and Cüppers's, penalization. These methods were gradually discarded by many strabologists, and at present time something like a comeback to surgical treatment is observed. That recurrence was due to the fact that the conservative methods, being improperly used, failed to give any effects at all, or provided only temporary improvement. The author emphasizes that the most serious cause responsible for the lack of any progress in the world strabology is that the cortical processes in the squint are not fully understood and that the causes of squint are constantly associated with the extraocular muscles.