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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    Section jfourtt)* DIAGNOSIS OF THE DISEASE. THE distinction of this visual affection from others, with which it may be confounded, does not appear to be difficult. The observations al- ready brought forward in the preceding section might suffice without any additional suggestions. At sea, this ailment commonly appears, after a cer- tain continuance of exposure to those circumstan- ces which may be supposed to be requisite to its production. The principal characteristic, is, that the patient complains of his defect of vision in the night-time; or, as commonly happens, he begins to complain of impaired vision in the twilight. If the countenance of a person in these circum- stances is closely noticed, a peculiarity ma) gene- rally be observed, by which the intelligent prac- titioner is enabled to determine, with tolerable certainty, the nature of the patient’s complaint, and more especially if the other phenomena, enu- merated in the history of the disease, are taken into consideration. The observer will also regard the time when the person begins to complain, the appearance of the eyes, the length of time, also, he may have been exposed to the probable causes of the complaint, the character of the individual,