THE CAUSE AND CURE OF ERRORS OF REFRACTION
I T has been demonstrated in thousands of cases that all abnormal action of the external muscles of the eyeball is accompanied by a strain or effort to see, and that with the relief of this strain the action of the muscles becomes normal and all errors of refraction dis appear. The eye may be blind, it may be suffering from atrophy of the optic nerve, from cataract, or disease of the retina; but so long as it does not try to see, the ex ternal muscles act normally and there is no error of re fraction. This fact furnishes us with the means by which all these conditions, so long held to be incurable, may be cured.
It has also been demonstrated that for every error of refraction there is a different kind of strain. The study of images reflected from various parts of the eyeball confirmed what had previously been observed, namely, that myopia (or a lessening of hypermetropia) is always associated with a strain to see at the distance, while hypermetropia (or a lessening of myopia) is always asso ciated with a strain to see at the near-point; and the fact can be verified in a few minutes by anyone who knows how to use a retinoscope, provided only that the instru ment is not brought nearer to the subject than six feet.
In an eye with previously normal vision a strain to see near objects always results in the temporary production of hypermetropia in one or all meridians. That is, the eye either becomes entirely hypermetropic, or some form