Fear of mirrors: An abnormal and persistent fear of mirrors. Sufferers experience undue anxiety even though they realize their fear is irrational. Because their fear often is grounded in superstitions, they may worry that breaking a mirror will bring bad luck or that looking into a mirror will put them in contact with a supernatural world inside the glass.

Mirrors and other reflective surfaces have long been associated with the strange or the bizarre. For example, in Greek mythology, Narcissus fell in love with his own image reflected in the water of a fountain. He thought he was seeing the image of a beautiful nymph. Unable to embrace or call forth the image, he pined away and was eventually transformed into a flower. In The Picture of Dorian Gray, a novel by Oscar Wilde, a portrait of a handsome young man begins to deteriorate, reflecting the corruption of the man's inner being. The portrait becomes a mirror reflecting the state of the young man's soul. The man eventually commits murder and suicide.

Fear of mirrors is termed "Eisoptrophobia," a word derived from the Greek "eis" (into) and "optikos" (vision, image, sight). Other English words derived from "optikos" include "optic" (relating to vision) and "optician," a technician who designs eyeglasses according to a prescription.