'Hoe men zich voor brillen behoeden kan' of de moeizame verspreiding van optische kennis in vroegmoderne medische kringen

In this essay it is shown that eyeglasses were not highly recommended in medical treatises of the Early Modern times. They were often not mentioned amongst the therapeutical advices for eye disorders, or, if they were, not without a certain reluctance. It is shown how this can be understood in view of commonly held opinions about the diseased body, and the way vision takes place. Eyeglasses did not fit within the holistic remedies in use. Oculists were ambiguous too, but on different grounds: whereas the conceptual background seemed not such an issue, they considered eyeglasses as a threat towards their profession. The patient himself seemed to be seduced by the effect of eyeglasses, though some doubts about its working would also push him to try other popular remedies. The attitude of physicians gradually changed during the seventeenth century. It is argued that this can be linked to the evolution in ocular anatomy, strongly influenced by optical insights, whereby the eye is no longer considered in relation to the body, but to the world outside. Eyeglasses are thus on the edge of different discourses. It is the dynamic interaction between all of them that makes Early Modern ophthalmology so interesting and complex.