Eyestrain (commonly called asthenopia) / by Ernest Clarke.

  • Ernest Clarke
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: Eyestrain (commonly called asthenopia) / by Ernest Clarke. Source: Wellcome Collection.

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    has led, as one might expect, to the pendulum swinging too much the other way. There is a tendency to assign asthenopia as the cause of numerous diseases that it can possibly be only the effect of, if even there is any con- nection. For instance, it has been claimed that eye- • strain will cause ancemia or constipation, and that the correction of as small an error of refraction as half a dioptre, or even less, will remove these complaints ! Stevens, of New York, says, Difficulties attending the functions of accommodating and of adjusting the eyes in the act of vision, or irritations arising from the nerves involved in these processes, are among the most prolific sources of nervous disturbances, and more frequently than other conditions constitute a neuropathic tendency. ^ His conclusions are based upon observations in 2692 cases of nervous diseases. He maintains that by correcting the ocular defect he has cured the disease in a large proportion of the cases. He includes in his list of cures, headache (83.6 per cent, cured), migraine, neuralgia (83.53 per cent, cured), spinal irritation and neurasthenia, chorea, epilepsy and mental disorders. He says that out of 118 cases of chorea in children examined by him, no less than 113 had some refractive defect, 78 suffering from simple hyperopia.^ A commission was appointed by the New York Neuro- logical Society in 1889 to report on the treatment of epilepsy and chorea by the correction of ocular defects, and the answer was that Stevens had not proved his case ^ Ranney asserts that he has cured or relieved epilepsy, neurasthenia, neuralgia, chorea, hystero-epilepsy, melan- 1 Functional Nervous Diseases, 1887, p. 21. 2 Op. cit., p. 91. 2 Oph. Rev., vol. ix., p. 83.