How to take care of our eyes : with advice to parents and teachers in regard to the management of the eyes of children / by Henry C. Angell.

  • Angell, Henry C. (Henry Clay), 1829-1911.
Date:
1879
Catalogue details

Licence: Public Domain Mark

Credit: How to take care of our eyes : with advice to parents and teachers in regard to the management of the eyes of children / by Henry C. Angell. 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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    effort is made to turn the eyes inward ; and if you continue to look at the finger in this position, the act will soon become painful. The convergence of in looking at a the eyes is also an effort, and is brought distance there i_.v i ^-u .l • j r i_ is no conver- about by a muscle on the outside of each §ence- eyeball, attached to the white of the eye on the side towards the nose. This muscle (M C, Figure A) we may call the muscle of conver- gence. There are other muscles which modify the action of this one, but they need not be considered here. THE NATURE OF WEAK SIGHT. Weak sight is therefore nothing more nor less than a disorder of the accommodative apparatus: Failure of the or, we may say, a disorder of the two accommodating or adjusting muscles of accommodation and conver- power of the eye. gence. In health, these two muscles work together in perfect harmony. If either one becomes affected, this harmony is disturbed, and weak or painful sight may follow; but the imme- diate occasion, usually, of weak sight is an over- worked, fatigued, sensitive condition of these muscles. It is plain, then, that as in distant vision Moderation tn^s muscular apparatus is not used, neceSryln011 and aS in near WOrk lt mUSt °f necessity using the eyes. be brought into service, if sight is weak