The refraction of the human eye : a critical study of the statistics obtained by examinations of the refraction, especially among school children / by B. Alex. Randall.

Randall, Burton Alexander, 1858-1932.

Date:: [1885]

Credit: The refraction of the human eye : a critical study of the statistics obtained by examinations of the refraction, especially among school children / by B. Alex. Randall. 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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$Looking backward over the long array of investigations wliich have been here grouped together, a few words of general comment seera per- missible before passing to our conclusions. It is very evident that the majority of the studies cited can make no claim to being the unimpeach- able foundation for our investigation of the refraction of the human eye; indeed few have been undertaken with the solution of any such question in view. The details of the methods employed in each examination would make clearer, perhaps, than is now the case, the true status and value of each ; but lack of space excludes them, and the writer is unwill- ingly forced to group the studies and marshal their results as his study of the original data indicates is correct, and to set them forth apparently solely upon his own authority. Careful study of the original records will show, however, that the records have been in no instance classified, recast, or emended, arbitrarily; and if any judgment has been passed not fully upheld by the data furnished by each investigator, it has only been in holding as competent some of the investigations which are not a priori clearly self-condemned. In view of the great preponderance of the hyper- metropic refraction in all investigations where its presence has been sought with a care in any degree adequate, it must be as evident to others as it is to the writer, that many of the studies giving low percentages in this matter cannot be correct. Such a conclusion, however, would by many be deemed a result of reasoning a 'posteriori., and has not been here drawn. For the figures given, unimpeachable accuracy cannot be claimed, especially when the sources from which they are derived are rarely free from palpable errors ; and confusion and error are too easy of entrance to have been entirely excluded in the writer's own work. All that repeated careful revision and verification can do has been sedulously employed to secure correctness, and where possible the data have been submitted for verification to the investigators themselves, to many of whom the writer's thanks are therefore due. It is then evident, that for the solution of the broader questions of the prevailing condition of refraction and other similar generalizations, few of the investigations thus far made are fully available; and it is to be hoped that future students of the subject will recognize these shortcomings and furnish us with fuller, broader, and more accurate data. The oppor- tunities to employ mydriatics in extensive studies will continue to be very rare ; it is therefore incumbent upon those who shall have such chances, if they would contribute fully to the elucidation of this important subject, to furnish at the same time data as complete as possible as to the vision without and with glasses, the accommodation and the apparent re- fraction, before the mydriatic, as well as the intraocular condition and the functional comfort of the eyes ; and to furnish proof, where possible, that the mydriatic had been pushed to full paralysis of accommodation. Thus only can the strict requirements of the subject be met. For those$