F.C. Donders: turning refracting into science
By B. Theunissen

Already during his lifetime F.C. Donders (1818-1889), the first director of the National Eye Clinic for the Poor at Utrecht, was celebrated as one of the most successful Dutch medical men ever. His renown has lived on to the present day. The marble gaze of his imposing statue watches over the central square of the city of Utrecht, and his name was recently immortalised in the F.C. Donders Institute for Ophthalmology of the University of Utrecht.

Franciscus Cornelis Donders was educated as a military health officer. In 1848 his talent for scientific work earned him a professorship at Utrecht University. After a visit to William Bowman's ophthalmological clinic in London in 1851, Donders decided to establish an ophthalmological clinic in Utrecht.

This clinic was the only one of its kind in the Netherlands at the time, and from the beginning it functioned at maximum capacity. Soon the need was felt for more roomy accommodations, and in 1858 the National Eye Clinic for the Poor opened its doors. The clinic was to gain an international reputation, not only as a hospital, but also as an institution for education and research in ophthalmology.

Donders was not a gifted surgeon. Most operations were performed by his second in command, Herman Snellen. Donders' research was of a scientific, physiological nature. His work focused on the physiology of the senses. He wrote, for instance, on the speed of mental processes and on the mechanisms of accommodation and of eye movements. The regularities that he found in the orientation of the eyes during eye movements are still known as Donders law.

The centrepiece of his scientific work concerned the anomalies of refraction and accommodation of the eye. These are the ordinary deviations of eyesight that can be corrected by lenses, such as myopia, hypermetropia, presbyopia, and astigmatism. The anomalies in question had all been known more or less since antiquity, and various explanations had been suggested. However, opinions on the nature and causes of the anomalies varied widely, and no large-scale, systematic investigations had yet been undertaken.

Donders was the first to undertake such investigations. His results on myopia, for instance, were based on the examination of more than 2500 patients of all ages. His data enabled him to draw graphs and curves illustrating the development of myopia with age. He also clarified the anatomical backgrounds of myopia and other anomalies. Thus he was the first to establish a clear difference between errors of refraction and errors of accommodation. Donders gave convincing reasons for separating presbyopia, farsightedness as a result of ageing, and hypermetropia, the farsightedness that is independent of age. Finally, the scale of Donders investigations enabled him to show that astigmatism, which was known at the time but was thought to be a rare phenomenon, was in fact fairly widespread.

The articles Donders wrote on these investigations attracted wide attention, especially after he had written a book on the subject, On the anomalies of refraction and accommodation of the eye (1864). Donders became the internationally acknowledged expert in the field.

The eyesight deviations that Donders studied could not be healed. What he did was explaining them. His explanations were of a purely scientific nature; they did not change the practice of correcting anomalies of sight. Before Donders and after Donders, therapy consisted in finding the correct lenses to restore sharpness of vision and this was, and still is, a matter of trial and error. Still, Donders could often help his patients better than the non-academic opticians and 'eye-doctors' of his time could. To begin with, Donders had better resources. The Utrecht eye clinic provided him with an array of instruments of which the average optician could only dream. He also had the latest literature in the field at his disposal and was abreast of developments in ophthalmology elsewhere. Donders ophthalmological knowledge, his clinical experience and his instruments regularly enabled him to arrive at a better diagnosis of patients who had been treated unsuccessfully by others. An example is his finding, mentioned above, that astigmatism was far more widespread than was generally assumed. Thanks to the series of cylindrical lenses that he had at his disposal, Donders could help many patients whose astigmatism had been overlooked until then.

So even though Donders' new physiological insights were not directly relevant for the practice of lens prescription, his activities as a whole did change the field. What had until then been a craft and a trade, performed by lens grinders and opticians, now became a scientific activity for which academic training was required. Put differently, Donders' scientific approach and academic resources enabled him to begin the medicalisation of the field of eyesight anomalies. In many Western countries, the prescription of lenses became a monopoly of academically trained ophthalmologists. Only recently have these tasks been returned to non-academic opticians again.

Bibliography
- F.P. Fischer and G. ten Doesschate, Franciscus Cornelis Donders (Assen, 1958).
- B. Theunissen, 'Turning refracting into a science. F.C. Donders and the medicalisation of lens prescription', Studies in History and Philosophy of Biological and Biomedical Sciences 31 (2000) 557-578.
- Isolde den Tonkelaar, Harold E. Henkes and Gijsbert K. van Leersum, Eye and instruments. Nineteenth-century ophthalmological instruments in the Netherlands (Amsterdam, 1996).