Strengthening the Eyes
by Bernarr A. MacFadden, Strengthening the Eyes; A System of Scientific Eye Training.
Exercises for the Pupil of the Eye
IT is a comparatively simple matter to exercise the little dilator and sphincter muscles which have to do with the enlarging and diminishing of the pupil of the eye. Under normal conditions of vigor these muscles scarcely need attention. It is only when the eyes are weak, and these muscles do not respond readily in accommodating the opening to various degrees and intensities of light, that special exercise is required.
Naturally, the only practical way to exercise these muscles is to find a method of exposing the eye in rapid succession to degrees of light of varying intensity. At night this may be done by turning an electric light on and off repeatedly for a minute or two. In the daytime one can stand in a room with one window, pulling the shade down to darken the room, and then raising it and looking out of doors. In either case try to see the various objects in the room when it is darkened. It is through this attempt to see in the dark that the dilator muscles will be especially stimulated, as the pupil enlarges as much as possible to enable you to see.
Exercising the pupil of the eye. This is best done in a dark room. At first, do not look directly at the light but at some white object, turning the light off and on at intervals of two or three seconds. You can soon accustom yourself to looking squarely at the light while turning it on and off. One minute or less will be sufficient.
When the electric light is turned on, or the shade raised, the greatest stimulation will be derived from looking directly at the light, or at the sun, for an instant, provided this does not involve the sensation of eye strain or discomfort. It might not be wise, however, to do this unless you are sure that your eyes are fairly strong. You can get sufficiently good results by looking at any white object when the light is turned on, for instance, the blank page of a book. Turn the light on and off at intervals of two or three seconds. If your eyes are sensitive to artificial light it may be better to practice this exercise in the daytime, pulling down the window shade and then raising it. One or two minutes of this exercise usually should be sufficient.