Treatise on the diseases of the eye : including the anatomy of the organ / by Carl Stellwag von Carion ; tr. from the 3rd German ed. and ed. by Charles E. Hackley and D.B. St. John Roosa ; with an appendix by the editors.
- Karl Stellwag von Carion
- Date:
- 1870
Licence: Public Domain Mark
Credit: Treatise on the diseases of the eye : including the anatomy of the organ / by Carl Stellwag von Carion ; tr. from the 3rd German ed. and ed. by Charles E. Hackley and D.B. St. John Roosa ; with an appendix by the editors. Source: Wellcome Collection.
Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.
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![SHADES. PROTECTIVE SPECTACLES. *] patient should stay in a room aitificially lighted, since inclosing the bed with a curtain renders the circulation of air in the room difficult, and will annoy the patient. When he remains in bed the formerly fashionable flat light-shades, which are placed before the flame, may be used, or even a sheet of rough paper fastened iu front of the flame, as occasion may require. In case a lamp is used, it will be best to make a rouud opening iu a sheet of paper, cut oval at one end so that it hangs over the shade, and then place it over the glass chimney. Gray paper, especially blotting-paper, is the best material for such shades. Light colored shades, especially the favorite light green or blue, do not answer the purpose, on accouut of the intensity of their color in transmitted light. It will be understood that brightly painted or perforated shades are still less desirable. Opaque shades, as, for example, tin ones, are even less useful on account of the contrast which they produce between shaded and illuminated places. 3. Eye-shades.—These can only he of use when we wish to keep the direct rays .of the san, or of any other intense light from the eye. They avail little or nothing against diffused light. In order to ward this off they must be placed at a very acute angle with the face. Even then the patient looks out of a very dark space, and the contrast produces the same effect as if he looked out of a dark cellar upon the bright sk}-. The material of which eye-shades are made is not of very great importance. It may be said, however, that shades of coarse gray paper, such as the wrappings of loaf-sugar, fastened on the head by means of a little baud, are most to be recom- mended on account of their flexibility, simplicity and cheapness. Green taffeta shades, fastened by wire, do not answer as well, since in direct sunlight they let in a great deal of green light; and the wire presses on the temple, and thus becomes unbearable. The thick pasteboard shades are very unpleasant on accouut of their stiffness. Eye-shades are evidently unnecessary in artificial illumination, lamp shades heing sufficient. In direct sunlight, broad-brimmed hats or caps, with large front-pieces, are more easily worn. 4. Veils.—These may be especially used by females aid children, whose cases de- mand that they should be allowe 1 to go out in the fresh air, even when they have irritated eyes. The best are the plain gray or black. Those of a yellow color are not advisable. 5. Protective Spectacles.—These are best made of smoke-gray glasses. Green glasses are not advisable, since in a bright light, they transmit a very intense and very dark green, approaching a yellow, which increases rather than diminishes the irritated condition. Blue glasses are to be preferred to green, as the blue color exerts a less severe impression upon the retina. Even these do not fully answer the purpose. Deep blue glasses, as experience teaches us, pain the eye in bright light. Pale blue glasses, on the other hand, furnish no effective protection. They weaken the light too little. They are only sufficient when we are dealing with a very evanescent condition of irritation, and here protective spectacles are nearly superfluous. Smole-gray glasses, London smoke, weaken the transmitted light very considera- bly, and this naturally in proportion to the depth of thtir shading. They enve'op all the objects in the visual field, as it were, in the twilight of evening, or of a very dark day; they adow the objects looked upon to be seen in their natural color, but with very much subdued intensity, and on the whole answei fully the purpose which may be reasonably ex] ected from wearing them. Such smoke-gray glasses may be obtained in all possible shades. These of a light color only are useful. Those glasses, whose color in reflected light approaches a black, darken the visual field toe much. They disaccustom the eyes to the light, and thus'render difficult the return to a normal illumination. They also hinder the distinct view even of near objects, and thus often cause the patient to strain his eyes and increase the irritated condition. Every one may convince himself](https://iiif.wellcomecollection.org/image/b2107902x_0029.jp2/full/800%2C/0/default.jpg)
