This complaint is caused by long-continued looking at minute objects; or exposure to glaring light, especially if combined with heat, and these exciting causes are aided by intemperance, stooping, tight neckcloths, too much sleep in bed, and any other circumstances capable of producing determination of blood to the head. Amaurosis may also be a consequence of organic change, inflammation, concussion, compression from extravasated blood, fractured bone, tumours or aneurisms, whether affecting the brain, optic nerve, or eye.

Sometimes the sight becomes suddenly dim, and is soon extinguished altogether; more frequently it becomes impaired by slow degrees, and at first is only so at intervals; after the eyes have been fatigued, for instance, or when the spirits are low, or the stomach disordered. Sometimes it commences as indistinct vision, or objects appear doubled, or one half only of the objects looked at is seen; or objects may appear crooked, disfigured or discolored; or they may be seen covered with patches; or the affection may commence as far-sightedness, or near-sightedness. The patient finds himself unable to estimate distances, and misses his aim when trying to snuff a candle, or do anything of that kind.

Treatment

If the complaint has suddenly followed some injury to the eye, such as a punctured wound, or blow on the naked eyeball, or exposure to a flash of lightning, or the patient had been engaged in occupations that necessarily tax the eye very severely, such as reading and writing much by candlelight; exposure to the intense light reflected from snow, staring at an eclipse of the sun, etc.

Or, if there are headache, giddiness, red, turgid countenance, with a hot skin and a hard pulse, and if there are frequent flashes of light, or streams of red-hot balls seen before the eyes, especially when stooping, or undergoing some active exertion.

Or if the complaint has followed a suppression of any accustomed evacuation, such as bleeding from piles, or the suppression of the monthly discharges from exposure to cold; or the sudden suppression of perspiration, or the drying up of an habitual eruption or ulcer, etc.,-in all these cases the anti-inflammatory treatment must be pursued. Leeches must be applied to the temple, and cupping or a blister to the back of the neck. Purgative medicines must be taken, and the diet must be low and unstimulating; and all employment of the eyes, and all violent bodily exertion should be abstained from. Blisters may also be applied behind the ears.