By the term use-abuse theory I mean for the purposes of this article all the major theories of change in refraction opposed to the biologic theory. The term is used to contrast two views as sharply as possible. Roughly, the use-abuse theory covers the school work, convergence-accommodation, poor lighting and bone formation theories. Near sightedness looms large and dominates the thinking of the school which favors this theory. The biologic theory stakes everything on heredity and growth. For its adherents, near sightedness is a serious state of refraction, but only one type of biologic refraction status. Myopia and its development do not dominate the thinking of the school favoring the biologic theory.
Frankly, both concepts are pure theories. Facts in full support of either are lacking. This article, therefore, only pretends to state the issue more sharply than has been done heretofore in this country and to add a small