On the morbid sensibility of the eye, commonly called weakness of sight / By John Stevenson.

  • John Stevenson
Date:
1811
Catalogue details

Licence: Public Domain Mark

Credit: On the morbid sensibility of the eye, commonly called weakness of sight / By John Stevenson. Source: Wellcome Collection.

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    buted this cheerful colour throughout the vegetable kingdom ? 1 must, however, beg to remark, that there is a very essential difference between looking at, and through green. A greater exertion of the organ of vision is un¬ questionably required in using green than zchite glasses, on account of their opacity. The objects too, seen through them, appear of a dingy yellowish hue, (a defect which I admit is greatly corrected by habit and ex¬ perience,) and when taken off, the impression of light must be proportionably stronger, and consequently more injurious to the sight. For by using green spectacles, especially those of a deep tint, the eye is subjected to frequent, and not inconsiderable variations in respect to the degree of light; and every such sudden and violent change, must of necessity he detrimental to the organ of vision. They can be considered as serving the purpose only of a shade, (which probably may, in many cases, be afforded better by other contrivances,) calculated to protect the
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