Stevens himself, "the crucial test" of the correctness of his theory. Yet no such result was observed. Nevertheless, in his later essay, he insists that "correction of the eyes of the patients does relieve their nervous symptoms. . . . This is no place," he says, before the Albany Institute, "to relate cures in medical practice; but, after a sufficiently extended and careful series of observations, continued during more than four years, I can safely prophesy that this principle will be found of more universal application, and more successful in its workings, than any which has been advanced for the mitigation of this class of affections."
The distressing confusion and disappointment resulting from the unbalanced action, in the over-sighted eye, between the arrangement for adjusting the lens and that for converging the eyeballs, is very clearly explained by Dr. Stevens in the same paper. Referring to its effect upon school-children he says:
Resuming now the consideration of near-sight, we proceed to suggest some of its principal causes, as follows:
1. Too early use by school-children of books, slates, and writing-paper, or copy-books, when blackboards and models would be better. Type and script letters and figures, and their primary combinations, at least, should never be taught from books, but from large and perfectly-formed models, printed on cards and hung on the wall. When the eye and the memory are sufficiently trained to easily recognize and name each letter and figure at sight, and when some knowledge has been gained of the power of letters and figures in combination, then the same forms in books will be at once familiar as old acquaintances, and may be studied without straining the sight. To train the hand without straining the sight presents a greater practical difficulty. In the large schools, of course, all the children cannot go to the black-board. But a considerable practice in drawing large lines and simple objects on good-sized slates, in a sort of free-hand style, should precede the formation of letters and figures; and, when these are begun, they should be made of generous size. A correct position, meanwhile, should be an imperative requirement; and, until it becomes habitual and easy, good work should be held to be of secondary importance. Hard slate-pencils and greasy slate-surfaces should not be permitted; both should be subject to systematic inspection.