The Physiomedical Dispensatory by William Cook, M.D., 1869
Description: Natural Order, Scrophulariaceae. This is a pretty little plant from four to six inches in height, found through the New England States and Canada, and quite abundant in Europe. Stem somewhat square, downy, branched, slender. Leaves opposite, less than half an inch in length, ovate. Flowers axillary, solitary, light blue or red, as long as the leaves, strongly two-lipped; upper lip concave, and two-lobed, lower lip three-lobed and spreading; lobes deeply emarginate. July. The small size of this plant causes it generally to be overlooked; and it is often confounded with the euphorbia hypericifolia, which also has the common name of eyebright. The latter article is acrid and poisonous; and may be distinguished by its purple and prostrate stem one or two feet long and much branched; by ifs yielding an acrid and milky juice wherever broken; and by its leaves having dark spots near the center.
Properties and Uses: The leaves are mildly stimulating and astringing, and exert a somewhat tonic influence. They act principally upon mucous membranes; and may be used to advantage in all excessive mucous discharges, as in leucorrhea, gonorrhea, coughs, catarrh of the bladder, and laxity of the bowels. They are best adapted to mild cases, but are reliable in their action; and are a valuable remedy in the peculiar summer complaints of children. Their common name refers to their decided efficacy as wash or poultice in weak eyes and congestion of the conjunctiva;, and in catarrhal ophthalmia. They are also reputed useful in the cough and headache that sometimes follow catarrhal affections. An infusion is made of an ounce of the leaves to a pint of hot water, and used in doses of two fluid ounces every four hours.
Medical Herbalism journal and medherb.com