Botanical name: 

The plant Euphrasia officinalis, Linné (Nat. Ord. Scrophulariaceae). Europe and America. Dose, 1 to 30 grains.
Common Name: Eyebright.

Principal Constituents.—An acrid, bitter principle and a volatile oil.
Preparation.—Specific Medicine Euphrasia. Dose, 1 to 60 drops.

Specific Indications.—Acute catarrhal diseases of the eyes, nose, and ears; fluent coryza with copious discharge of watery mucus. "Secretion of acrid mucus from the eyes and nose with heat and pain in the frontal sinus" (Scudder).

Action and Therapy.—An admirable remedy for acute catarrhal inflammations of the nasal and ocular membranes, with profuse, watery secretion or abundant flow of acrid mucus, and attended with heat, pain, burning, and sneezing. It is one of the most certain agents in acute coryza and in mucous ophthalmia, with abundant lacrimation. It is equally effective when acute catarrhs extend to the ears through the Eustachian passages, and are attended by earache, headache, sneezing, and coughing. Euphrasia is useful both to prevent and to relieve, in the early stages, acute frontal sinusitis. During or following measles it controls the distressing catarrhal symptoms. In all disorders its most direct indication is profuse watery discharge with acute inflammation or irritation. It is less valuable in the catarrhal disorders of the gastro-intestinal tract.

Euphrasia is a striking example of a simple drug that has acquired a great and exaggerated reputation in folk-medicine. Euphrasia means "good cheer, or delight," and refers to its reputed "effects upon the spirits through its benefits to the sight" (Millspaugh). It once enjoyed a great but unsustained reputation as a cure for all diseases of the eye, even becoming the theme of the poet's pen—Milton referring to it in Paradise Lost, as purging "the visual nerve." It came into Eclectic medication from Homeopathic sources, but with some modifications of symptomatology. The characteristic symptom calling for it is acridity of the discharges, and this is emphasized by Homeopathic writers. It matters little whether the discharges be thin and watery, or thick and yellow—they are free, biting and excoriating, making the lids red and sore. It is essentially a remedy for catarrhal states and for superficial, not deep, eye disorders. Accumulation upon the cornea of sticky mucus befogging vision is a euphrasia indication. With such ocular disorders is usually more or less coryza, which may be far less hot and biting, or may be bland. The drug has proved especially useful in the epidemics of la grippe in recent years to control the profuse lachrimation. Euphrasia sometimes proves serviceable in hay fever, having the characteristic discharges above mentioned.

The Eclectic Materia Medica, Pharmacology and Therapeutics, 1922, was written by Harvey Wickes Felter, M.D.