On the pathogeny of squint / by Professor Donders ; translated from the German, with a preface, by E. Perceval Wright.

  • Donders, F. C. (Franciscus Cornelis), 1818-1889.
Date:
1864
Catalogue details

Licence: Public Domain Mark

Credit: On the pathogeny of squint / by Professor Donders ; translated from the German, with a preface, by E. Perceval Wright. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    in the least. In the monographs it is not much better. Is it then strange that the pathogeny of strabismus is still so obscure ? It appears to be part of man's nature to attribute to each phenomenon an external cause, and to admit as such the first that presents itself. Even patho- logy has not yet entirely liberated itself from this levity and credulity. As far at least as strabismus is concerned, its causation has often been searched for in the most fortuitous circumstances—looking: for informa- tion to nurses and mothers—while the veritable origin of the disease, which resides in the form of the eye, has been overlooked. A few years ago we became acquainted with one of the anomalies of refraction—hypermetropia—in which the focal point of the dioptric system, in a state of rest, lies behind the retina. After having dis- covered the slighter degrees of this anomaly, which may exist in a latent condition, I quickly came to the conviction that it is on it that asthenopia and convergent strabismus depend—whose origin until then had remained problematical. Elsewhere1 I have treated, in detail, on hypermetropia as a cause of asthenopia; I have admitted that the insufficiency of the recti interni muscles, as pointed out by von Graefe,2may produce pathological phenomena having a great affinity with those of asthenopia, following hypermetropia; but I have added that cases of this kind are relatively very rare; we find, in studying the causes of diverging strabismus, that they occur very frequently with a certain degree of myopia. Further, I have mentioned that the greater the degree of the accommodation ^ is, so much the greater can the hypermetropia be without causing asthenopia; and, therefore, the later the asthenopia is in developing itself the less is the hypermetropia; I may add that the age at which asthenopia commences, corresponds very nearly to the denominator of the fraction which expresses the degree of hypermetropia. Lastly, I have remarked, that the feebleness of the accommodation, whether owing to general or local causes, favours the development of asthenopia. I have since published some observations3 on diminution of accommodation, of a diphtheritic origin, which had produced symptoms, which one could never determine, at first sight, from those of asthenopia from hypermetropia. 1 Ametropie en bare gevolgen. Utrecht, 1860, bl. 30. Archiv fur Ophthalmologic. Bd. vi. 1, S. 78 u. f. 2 Archiv fur Ophthalmologic Bd. iii., Abth. 1, S. 308. » Tijdschrift voor Geneeskunde, 1860. D. vi., bl. 657. Archiv fur die Holland. Beitriige zur Natur—und Heilkunde von Donders und Berlin. Bd. ii., S. 453.