Emily Dickinson Lexicon

AM-AUR-O'SIS, n. [Gr. αμαυρος, obscure.]

A loss or decay of sight from a palsy of the optic nerve, without any visible defect in the eye, except an immovable pupil; called also gutta serena. Sometimes the disease is periodical, coming on suddenly, continuing for hours or days, and then disappearing. It has sometimes been cured by electricity. – Encyc. Coxe.