Observations on hemeralopia; or, Nocturnal blindness, with cases, and practical illustrations / by Andrew Simpson.

Date:
1819
Catalogue details

Licence: Public Domain Mark

Credit: Observations on hemeralopia; or, Nocturnal blindness, with cases, and practical illustrations / by Andrew Simpson. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    frequently different in particular individuals; and it is a sense, likewise, which is liable to gradually introduced modification, agreeable to its employ- ment, in different occupations and professions. This is sometimes particularly and expressively illustrated in the illiterate, whose habits of atten- tion are very restrained or confined, and who com- monly use their eyes for the grossest and most unrefined observation,—and the philosophic me- chanician, who, from the peculiarity of his employ- ment, uses his eyes for ascertaining the properties, and frequently the adjustment of delicate struc- tures, and the conjunction of the minima vuibilia. This invaluable instrument, the eye, therefore, by prolonged habituation to jmrticular ways or forms of adaptation, seemingly becomes familiarized to the instantaneous act of perceiving and discern- ing, so that ultimately, the performance seems to be intuitively accomplished. And, moreover, it is the intermedium to intellectual comprehension (but which, from custom grown into habit, be- comes imperceptible) and conclusive determina- tion, which to those unacquainted is wholly in- comprehensible. The eye, besides being contributive to the purposes of ordinary guidance and intellectual improvement, is also an instrument particularly serviceable in apprehending and distinguishing the appropriate and characteristic appearances of