On the anomalies on accommodation and refraction of the eye : with a preliminary essay on physiological dioptrics / by F. C. Donders ; translated from the author's manuscript by William Daniel Moore.

  • Donders, F. C. (Franciscus Cornelis), 1818-1889.
Date:
1864
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Licence: Public Domain Mark

Credit: On the anomalies on accommodation and refraction of the eye : with a preliminary essay on physiological dioptrics / by F. C. Donders ; translated from the author's manuscript by William Daniel Moore. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

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    We should bear in mind, that in the stationary refraction of the one eye, the same glass can be useful only for a given distance. The principal objective phenomenon of paralysis of accommodation—the wide, immovable pupil—was the first to attract attention, and was designated by the ancients under the term mydriasis. But a dilated pupil being a symptom of amaurosis, the disturbance of vision in simple paralysis of accommodation was also looked upon as a slight degree of amblyopia, or was ascribed to the excess of incident light. Even in our own day this error is not unusual. It was in fact incredibly long, before ophthal- mologists in general had a sufficiently correct idea of accommodation properly to comprehend its deviations. I know not who was the first to suggest clearer and correct ideas. But it seems as if these were included in the discovery of the principle of accommodation, and on that discovery, as it were, spontaneously came to light in different quarters, although Cramer, who discovered that principle himself, was still deceived as to the nervous influence in accommodation. A more accurate observation of the cases which pre- sented themselves certainly proceeded from the introduction of the determination of the range of accommodation. Mydriasis, as a symptom of blindness, almost always depending on a cerebral cause, does not belong to my subject. With respect to mydriasis, independent of paresis of accommodation, I might probably also be silent. I believe, in fact, that in the great majority of cases, either the paresis of accommodation was overlooked, or the existence of mydriasis was lightly assumed. Certainly it has not been sufficiently kept in view, that young children usually have large pupils, and thus all sorts of causes have been called upon, but especially the presence of worms, to explain a pheno- menon which, in childhood, needed no explanation. Accurate determinations of the size of the pupil, the light being the same, may in each case be required: in my own investigations, in which the measurement was effected with the ophthalmometer, I was struck with the great similarity of the pupil in the same individuals at different times, the illumination and the accommodation only being equal. Von Graefe says he has observed mydriasis to be a precursor of mania.—That an irritated condition of the sympathetic nerve in the neck (irritation of the abdominal portion in animals does not produce mydriasis) might lead to uncomplicated mydria- sis, without any influence on the accommodation, is, a priori, very probable; but the cases in which the occurrence thereof should be proved are almost wholly wanting in literature, and in nature I have so far not met with them. § 47. Paresis of Accommodation ajter Diphtheria faucium and weakening of Accommodation For some years past a malignant disease, known by the name of diphtheria faucium, or angina diphtheritica (better diphtherina), has pre- vailed in certain countries of Europe. In the commencement of i860 it began to manifest itself in several places in the Netherlands, where it is still prevalent, and even in the course of the past year carried many to the grave. In France and elsewhere, different forms of paralysis had been observed, as sequelae of this diphtheria. Among these mention had been made of disturbance of vision, but without just appreciation of its nature. Soon after the occurrence of the disease, cases presented themselves to me, to the connexion of which with the angina in ques-