A practical essay on hemeralopia, or night-blindness, commonly called nyctalopia : as it affects seamen and others, in the East and West Indies, China, the Mediterranean, and all tropical climates ; in which a successful method of curing the disease is detailed / by Mr. R.W. Bampfield ... ; communicated by Dr. Roget.

  • Bampfield, R. W. (Robert William), -1827.
Date:
1812
Catalogue details

Licence: Public Domain Mark

Credit: A practical essay on hemeralopia, or night-blindness, commonly called nyctalopia : as it affects seamen and others, in the East and West Indies, China, the Mediterranean, and all tropical climates ; in which a successful method of curing the disease is detailed / by Mr. R.W. Bampfield ... ; communicated by Dr. Roget. Source: Wellcome Collection.

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    the iris bestows a peculiar susceptibility to be af¬ fected with night-blindness; as little reason is there for believing, that the size and form of the eye confers a peculiar susceptibility*. In general, the constitutional health does not suffer in idiopathic cases, except that the patient sometimes becomes irritable and apprehensive. The appearance of the eyes does not always indi¬ cate a state of disease, nor is it often perceptibly altered from its appearance in health, unless the disease, from long duration, be advanced to the worst stage I have described. In this case the pupil is often contracted, and the eves and actions of the patient evince marks of painful irritation, if the eyes are exposed to a vivid light, or if he looks upwards ; but if they meet the direct rays of the sun, which in the tropics are always powerful, or a strong glaring reflection of them, pain and tempo¬ rary blindness are induced, from which the patient recovers, by closing his eyelids, for a time, to ex¬ clude the rays of light, and by retiring to the shade. The pupil of the eye is considerably dilated, both by day and night, in the proportion of about one case in twelve, and at night the pupil is often di¬ lated and does not perform its expansions and con¬ tractions, when exposed to the moon, or artificial light. The cases attended with dilated pupil were * Magnos verb, potius quam parvos oculos habebant. Hip¬ pocrates, lib. vi. sect. vii.
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