Before revision: First International Ophthalmological CongressWhen 150 ophthalmologists from 24 countries gathered in Brussels, Belgium in 1857 for the First Periodic International Congress of Ophthalmology (), the International Council of Ophthalmology (ICO) was established .
After revision: A call to ophthalmologists and physicians interested in the field was issued on January 15, 1857 , by an organizing committee formed by the editorial board of Annales d'Oculistique to plan a special ophthalmology congress .