The Eye Resents Glasses 83
frequently observe that their sight has improved. As a matter of fact the sight always improves, to a greater or less degree, when glasses are discarded, although the fact may not always be noted.
That the human eye resents glasses is a fact which no one would attempt to deny. Every oculist knows that patients have to "get used" to them, and that sometimes they never succeed in doing so. Patients with high de grees of myopia and hypermetropia have great difficulty in accustoming themselves to the full correction, and often are never able to do so. The strong concave glasses required by myopes of high degree make all objects seem much smaller than they really are, while convex glasses enlarge them. These are unpleasantnesses that cannot be overcome. Patients with high degrees of astigmatism suffer some very disagreeable sensations when they first put on glasses, for which reason they are warned by one of the "Conservation of Vision" leaflets published by the Council on Health and Public Instruc tion of the American Medical Association to "get used to them at home before venturing where a misstep might cause a serious accident."1 Usually these difficulties are overcome, but often they are not, and it sometimes hap pens that those who get on fairly well with their glasses in the daytime never succeed in getting used to them at night.
All glasses contract the field of vision to a greater or less degree. Even with very weak glasses patients are unable to see distinctly unless they look through the center of the lenses, with the frames at right angles to the line of vision; and not only is their vision lowered if they fail to do this, but annoying nervous symptoms,
1 Lancaster: Wearing Glasses, p. 15.