The art of preserving the sight unimpaired to an extreme old age : and of re-establishing and strenthening it when it is become weak ... To which are added observations on the inconveinces ... of common spectacles / By an experienced ocultist [G.J. Beer].

  • Beer, Georg Josef, 1763-1821
Date:
1824
Catalogue details

Licence: Public Domain Mark

Credit: The art of preserving the sight unimpaired to an extreme old age : and of re-establishing and strenthening it when it is become weak ... To which are added observations on the inconveinces ... of common spectacles / By an experienced ocultist [G.J. Beer]. Source: Wellcome Collection.

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    dangerous is that ill-understood economy which only permits the use of one candle spect to patients suffering under that very extraor- dinary disorder, called ‘‘ Nyctolopia,” by which, though they see extremely well in the day, they become so completely blind on the approach of evening as to be totally incapable of conducting themselves. This complaint is principally, indeed, confined to tropical climates, and evidently pro- ceeds, in a great measure, from relaxation, and partly, perhaps, from exposure to the moon-beams whilst sleeping, a fact particularly noticed by medi- cal men who have had the care of such patients, ~ both in the East and West Indies. | I know not what credence is to be given to some accounts which state that the /us¢ nature, or white people, born amongst the African negroes, and also some of the Indian tribes on the Isthmus of Darien, have a greater facility of sight in the dark than when exposed to day-light. These people have been called “‘ Moon-eyed;” and Dr. Priestley at- tempts to account for the circumstance by the pro- -bability of their choroides being of a white or light eoloured texture, and not dark, as in all others of ;he human species, in like manner as cats, bats, and other nocturnal animals; but he confesses that he never met with any account of ocular dissections of