in medicine and surgery, the name of a disease in the eye, wherein the crystalline humour is turned of a bluish or greenish colour, and its transparency hereby diminished.—The word comes from γλαυκός, κάμιος, "sea green, sky-coloured, or greyish."

Those in whom this disorder is forming, discover it hence, that all objects appear to them as thro' a cloud or mist; when entirely formed, the visual rays are all intercepted, and nothing is seen at all.

It is reckoned incurable, when inveterate, and in aged persons; and even under other circumstances, is very difficult of cure, externals proving of little service.

The internals best suited to it, are those used in the gutta serena. Jul. Cæsar Claudius, Conf. 74, gives a remedy for the glaucoma.

The glaucoma is usually distinguished from the cataract or suffusion, in this, that in the cataract the whiteness appears in the pupil, very near the cornea; but it shows deeper in the glaucoma.

Some late French authors, however, maintain the cataract and glaucoma to be one and the same disease. According to them, the cataract is not a film, or pellicle, formed before the pupil, as had always been imagined; but an insufflation or induration of the humour itself, whereby its transparency is prevented; which brings the cataract to the glaucoma. According to Mr Sharp, the glaucoma of the ancient Greeks is the present cataract; but M. St Yves says it is a cataract accompanied with a gutta serena. See Surgery.