Observations on hemeralopia; or, Nocturnal blindness, with cases, and practical illustrations / by Andrew Simpson.

Date:
1819
Catalogue details

Licence: Public Domain Mark

Credit: Observations on hemeralopia; or, Nocturnal blindness, with cases, and practical illustrations / by Andrew Simpson. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    tion, which is grammatically and legitimately applicable to an affection of the eyes of a descrip- tion diametrically opposite, in which the eyesight is most serv iceable in an obscure light; it should therefore be denoted by the term Hemeralopia. How the denomination Nyctalopia should have been appropriated, by many, most inconsistently, to this complaint, appears altogether inexplicable. The Hemeralopia, or, positively, day-sight, and negatively, nocturnal blindness, has been nominal- ly mentioned, as an occasional disease, or symptom of disease, but of the disorder itself, no intelligible or satisfactory information has been supplied. T1 lis affection of the eyes probably never subsists, as an entirely topical, and original, and simple disorder, but may generally or rather invariably be considered, as symptomatic of some derange- ment of the healthy condition of the constitution. The assignment of a nosological character and locality to this affection, may in some measure facilitate and regulate the fulfilment of the fol- lowing discussions, which relate especially to this complaint; and which are principally derived from immediate observation.—The late Professor Cullen seems to have ranked it under his fourth Class, and first order, Dysesthesia;, defined in these words : “ Sensus depravati aut deleti ex or- ganorum externorum vitio. From this station given to the disorder, it would appear, that the