Report on the influence of school-books upon eyesight / British Association for the Advancement of Science.

  • British Association for the Advancement of Science.
Date:
1913
Catalogue details

Licence: In copyright

Credit: Report on the influence of school-books upon eyesight / British Association for the Advancement of Science. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    birth the eye has a volume equal to about half that of the full-grown eye ; the materials of which it is built are comparatively soft and yielding; the functional power of the visual apparatus is merely a perception of light. By growth and develop- ment, rapid at first, slower later on, the eye tends progressively to acquire the dimensions and the powers of the normal completed organ. Nutrition by healthy blood, and the natural stimulus of voluntary use, are essential to this process. We know by experience that in early infancy disease may arrest the growth of the eye, and that suspension of use, as when a serious ophthalmia prevents an infant for many weeks from attempting to use its eyes, may check functional development to an extent which cannot after- wards be made good. On the other hand, exces- sive efforts, due to unnatural demands on the eyesight, are apt to be injurious in the opposite direction. Unfortunately there is evidence to show that the demand made on the eyesight of school children is not infrequently excessive. At the age when school life begins the visual apparatus is still immature. The orbits, the eyes themselves, and the muscles and nerves which move them, have still to increase considerably in size. The various brain-structures concerned in vision have not only to grow but to become more complex. The intricate co-ordinating mechanism which later will enable the eyes, brain, and hand to work together with minute precision is awaiting develop- ment by training. The refraction of the eyes is not yet fixed. It is usually more or less hyper- metropic, with a tendency to change in the direction of normal sight; in other words, it has not reached the ideal condition in which the eyes see distant objects without accommodative effort, but is tend-