Gutta Serena, or Amaurosis, signifies the loss of sight, without any other visible cause or defect in the eye ; except that the pupil (or the round hole for admitting the rays of light) is generally deprived of its power of contraction.
Numerous are the causes from which this unfortunate blindness may arise; but the principal of them are nervous and paralytic affections. Violent contusions of the head; apoplectic fits ; hot baths; suppression of catarrhs, or periodical evacuations; metallic cosmetics ; drunkenness ; sudden flashes of lightning; repulsion of cutaneous eruptions; long fasting; frequent exposure to the rays of the sun ; violent exercise and passions, especially terror and anger; as well as purgatives, rheumatisms, sneezing; explosion of gums ; copious blood-letting; vomiting; worms, etc. all may occasion amau-rosis.
Among the remedies which have been found the most effectual, for removing this melancholy disease, are electricity; the cold bath ; hot embrocations, or blisters containing antimonial tartar, applied to the spine; leeches to the eyes of plethoric patients ; the magnet fastened to the nape of the neck, and a bag of iron-filings placed over the eyes; agitation of the frontal nerve; artificial ulcers; scarifications, or issues and blisters on the back part of the head, kept open for a considerable time; cupping; sina pisms, etc. while the body should never be suffered to become costive. For this purpose, we preferably recommend small doses of tartarized kali with Peruvian bark, namely, one or two drams of the former, and one or two scruples of the latter, to be taken once a-day, or oftener, as occasion may re-quire. - Mercurial remedies have also been used with great advantage ;. but they ought to be regularly prescribed.
There is another disease, called cataract, namely, a dimness or loss of sight from the interposition of an opaque film, either in the eye itself, or in the eye-lids. This malady generally takes place by imperceptible degrees ; it is often consequent to inflammations of the eyes, and arises from the abuse of spirituous liquors, external injury, and mortification; acrid vapours, etc. In the commencement of this complaint, similar remedies to those mentioned for the cure of gutta serena, may be used with advantage : beside which, emollient cataplasms and fomentations are of service, to check the progress of the affection. If, however, it has continued for some time, the cataract must be couched, or extracted by the skilful hand of a surgeon ; as there is no other prospect of removing it ; though electricity and mercurial purgatives, together with a poultice of fresh hemlock constantly kept upon the eye, and a permanent blister on the neck, are said to have sometimes afforded relief.