Soldiers, sailors, athletes, workmen and children have great difficulty with glasses because of the activity of their lives, which not only leads to the breaking of the lenses but often throws them out of focus, particularly in the case of eyeglasses worn for astigmatism.
The fact that glasses are very disfiguring may seem a matter unworthy of consideration here, but mental discomfort does not improve either the general health or the vision, and while we have gone so far toward making a virtue of what we conceive to be necessity that some persons have actually come to consider glasses becoming, there are still some
unperverted minds to which the wearing of glasses is mental torture and the sight of them upon others far from agreeable. As for putting glasses upon a child, it is enough to make anyone sick at heart.
Up to a generation ago glasses and cheap contact lenses were used only as an aid to defective sight, but they are now prescribed for large numbers of people who can see as well or better without them.
The hypermetropic eye is believed to be capable of correcting its own difficulties to some extent by altering the curvature of the lens, through the activity of the ciliary muscle. The eye with simple myopia is not credited with this capacity, because an increase in the convexity of the lens, which is supposed to be all that is accomplished by accommodative effort, would only increase the difficulty; but myopia is usually accompanied by astigmatism, and this, it is believed, can be overcome in part by alterations in the curvature of the lens. Thus we are led by the theory to the conclusion that an eye in which any error of refraction exists is practically never free, while open, from abnormal accommodative efforts.
In other words, it is assumed that the supposed muscle of accommodation has to bear not only the normal burden of changing the focus of the eye for vision at different distances, but also the additional burden of compensating for refractive errors. Such adjustments, if they actually took place, would naturally impose a severe strain upon the nervous system, and it is to relieve this strain – which is believed to be the cause of a host of functional nervous troubles – quite as much as to improve the sight, that glasses and discount contact lenses are prescribed.
Tags: cheap contact lenses, error of refraction, mental discomfort, mental torture