In the 1830s and 1840s, a particular disease named ‘military ophthalmia’, a contagious inflammation of the eyes that reigned most forcefully among soldiers, turned into an epidemic in Belgium, spreading between the army and the general population. This article scrutinizes the efforts of the Belgian military health service to contain the epidemic. It places the actions of the Belgian army doctors within a broader development : the emergence of ophthalmology as a specialized medical subfield, in which also ‘civil’ physicians participated.