A practical treatise on the diseases of the eye / by William Mackenzie ; to which is prefixed an anatomical introduction explanatory of a horizontal section of the human eyeball by Thomas Wharton Jones.

  • Mackenzie, William
Date:
1854
Catalogue details

Licence: Public Domain Mark

Credit: A practical treatise on the diseases of the eye / by William Mackenzie ; to which is prefixed an anatomical introduction explanatory of a horizontal section of the human eyeball by Thomas Wharton Jones. Source: Wellcome Collection.

    1020/1156
    ASTHENOPIA. attack, the pupils do not present more than a medium degree of dilatation. In some instances, indeed, the eyes appear dull, languid, and inanimate, having lost the expression of force and intelligence, and acquired one of feebleness and indecision; but in general they show no marked sign of disease. Asthenopia, in the ordinary run of cases, is unattended by any in- creased sensibility, intolerance of light, or pain in the organs of vision, unless the patient is in the way of forcing his eyes to con- tinued exertion even during the attack. Theuj^'indeed, pain is felt m the eyes and head. Some patients, however, complain of pain in the upper part of the eyeball, as if it had received a blow, even when their eyes are at rest. Pain down the middle of the forehead is also a symptom which many mention as being almost constantly present. The tongue is generally clean; sometimes it is tumid, and im- pressed round the edges by the teeth. The appetite is tolerably good, and the bowels regular. The disease rarely appears to be con- nected with any disordered state of the digestive organs. The habit of body of asthenopia patients is generally delicate. Paleness of the face and coldness of the extremities indicate the feebleness of their circulation. We rarely, if ever, meet with the disease in robust or plethoric subjects. On the contrary, those who suffer from asthenopia are, with few exceptions, wan and ill-fed; frequently thin girls, whose bodies are enfeebled and minds depressed by a sedentary life, want of air and exercise, and other causes. Asthenopia is rarely observed to commence in those who have already reached the middle period of life, but almost exclusively takes its origin in childhood or youth. Commencing at a very early age, it is apt to continue through life. Females are as frequently the subjects of the disease as males ; but it seems very seldom connected with any disorder of menstruation. Diagnosis. — The vulgar are apt to include every sort of disease of the eye under the term weak sight; nor are medical authors free from the error of jumbling a variety of disorders under the same appellation. The diseases with which asthenopia is most apt to be confounded are photophobia, incipient myopia, presbyopia, night or day blindness, and amblyopia or incomplete amaurosis. 1. Photophobia. The photophobia attending inflammation of the conjunctiva, caused by the heat which accompanies strong artificial light, and especially gas-light, is sometimes confounded with asthe- nopia. The inflammation in question is marked by a hot and irritable state of the eyes, which feel dry and stiff, and at length become painful and itchy, so that the patient is obliged to be continually rubbing them; These symptoms arise from a suppression of the secretion of the conjunctiva; but the disease being unchecked by rest and other means, the conjunctiva becomes much more inflamed, and begins to secrete puriform mucus. The patient, as in asthenopia, is forced to abandon the occupations he had been pursuing; but the slightest attention will enable the practitioner to distinguish the photo])h()bia of this or of any other ophthalmia from asthenopia. 'i. Myopia. It sometime happens that young persons, about the