People were instructed as follows in Strengthening the Eyes, published in 1925: “A weak solution of salt and water or a dilute solution of boric acid and water, is the best for this purpose, under ordinary conditions. These solutions must on no account be strong. The water must not be brine, nor the boric acid solution too strong. The water should usually be cool, or lukewarm; but the temperature must depend upon circumstances. In certain inflammatory conditions of the eye, it is often advisable to have the water quite cold, while, on the other hand, in all injuries and local affection which render the eye sore or tender, it is best to bathe it in warm or hot water--at least at first. The bath, as a rule, should not last more than twenty or thirty seconds for each eye, and should be followed by a blinking of the eye--which, however, will probably follow automatically.
The eye-cup is filled with whatever solution is to be used, the head leaned forward and the cup placed over the eye; then the head is tilted backward, and the eye under the cup opened and closed a number of times. The same operation is repeated with the other eye. It is a good thing not to keep the cup against the eye for too long a time, owing to the suction which develops in consequence. It should be removed and re-applied several times.
As regards medicinal substances to be used in the water, there are but few of these which can be recommended. A small percentage of salt is often strengthening to the eyes, but a heavy brine is irritating and injurious. A dilute solution of boric acid is often beneficial, as it tends to cleanse the eye and wash out irritating substances. Apart from these solutions, it is safe to say that ordinarily, the further the patient keeps from "eye lotions" and concoctions of that sort, the better. These eye baths should have the effect of strengthening and stimulating the eyes in a wholesome, hygienic manner, without irritation. Cases of weak and dull eyes are especially helped by them, and they are helpful in practically every case of eye disease and defect, where they are not distinctly contra-indicated.”
