956. _Of Preservers, and Rules for the Preservation of Sight._--Though it may be impossible to prevent the absolute decay of sight, whether arising from age, partial disease, or illness, yet, by prudence and good management, its natural failure may certainly be retarded, and the general habits of the eyes strengthened, which good purposes will be promoted by a proper attention to the following maxims:-- 1. Never sit for any length of time in absolute gloom, or exposed to a blaze of light. The reasons on which this rule is founded, prove the impropriety of going hastily from one extreme to the other, whether of darkness or of light, and show us that a southern aspect is improper for those whose sight is weak and tender. 2. Avoid reading small print. 3. Never read in the dark; nor, if the eyes be disordered, by candle-light. Happy those who learn this lesson betimes, and begin to preserve their sight before they are reminded by pain of the necessity of sparing them. The frivolous attention to a quarter of an hour in the evening, has cost numbers the perfect and comfortable use of their eyes for many years; the mischief is effected imperceptibly--the consequences are inevitable. 4. The eye should not be permitted to dwell on glaring objects, more particularly on first waking in the morning; the sun should not, of course, be suffered to shine in the room at that time, and a moderate quantity of light only be admitted. It is easy to see that, for the same reasons, the furniture of a bed should be neither altogether of a white or red color; indeed, those whose eyes are weak, would find considerable advantage in having green for the furniture of their bed-chamber. Nature confirms the propriety of the advice given in this rule; for the light of the day comes on by slow degrees, and green is the universal color she presents to our eyes. 5. The long-sighted should accustom themselves to read with rather less light, and somewhat nearer to the eye than what they naturally like; while those that are short-sighted, should rather use themselves to read with the book as far off as possible: by this means, both would improve and strengthen their sight; while a contrary course will increase its natural imperfections.