There is nothing which preserves the sight longer than always using, both in reading and writing, that moderate degree of light which is best suited to the eye: too little, strains them—too great a quantity, dazzles and confounds them. The eyes are less hurt by the want of light, than by the excess of it: too little light never does any harm, unless they are strained by efforts to see objects to which the degree of light is inadequate; but too great a quantity has, by its own power, destroyed the sight. Thus, many have brought on themselves a cataract, by frequently looking at the sun or a fire; others have lost their sight by being brought too suddenly from an extreme of darkness into the blaze of day. How dangerous the looking on bright, luminous objects, is to the sight, is evident from its effects in those countries which are covered, the greater part of the year, with snow, where blindness is exceedingly frequent, and where the traveller is obliged to cover his eyes with crape, to prevent the dangerous and often sudden effects of too much light: even the untutored savage tries to avoid the danger, by framing a little wooden case for his eyes, with only two narrow slits. A momentary gaze at the sun will, for a time, unfit the eyes for vision, and render them insensible to impressions of a milder nature.
957. The Feet—Should be washed in cold water every morning, and wiped very dry. Stockings, if too small, cripple the feet as surely as small shoes. Always be careful to give the foot room enough, and you will be rarely troubled with corns. When the toe-nails have a tendency to turn in, so as to be painful, the nail should always be kept scraped very thin, and as near the flesh as possible. As soon as the corner of the nail can be raised up out of the flesh, it should be kept from again entering, by putting a tuft of fine lint under it.
958. For Sore Feet.—The thin white skin which comes from suet, is excellent to bind upon the feet, for chilblains. Rubbing with Castile soap, and afterwards with honey, is likewise highly recommended.
959. A Vapor-Bath at home.—Place strong sticks across a tub of water, at the boiling-point, and sit upon them, entirely enveloped in a blanket, feet and all. The steam from the water will be a vapor-bath. Some people put herbs into the water. Steam-baths are excellent for severe colds, and for some disorders in the bowels. They should not be taken without the advice of an experienced nurse or physician. Great care should be taken not to renew the cold after; it would be doubly dangerous.