The first mirror was quite likely a quiet pool in which one caught a fleeting reflection of an image of oneself. The early Greeks had mirrors that were made of circular pieces of polished bronze, sometimes with richly adorned handles. The early Egyptians also had bronze mirrors, highly polished dishes, usually with graceful and decorative handles.
Since early times the mirror has been used in divination, in attempts to read the future or the past. In ancient Greece divination performed by means of water and a mirror was so popular and so widely practiced that it was given a definite name—"catoptomancy." There are still seers and fortune-tellers called "scryers" who "see" the past and the future in crystals and mirrors.
An early belief was that one saw the will of the gods in the mirror. To break a mirror accidentally, therefore, was interpreted as an effort on the part of the gods to prevent the person from seeing into the future. This was construed as a warning that the future held unpleasant things.
It was not until 1688 that glass mirrors were invented. In that year, a Frenchman, Louis Lucas, invented plate glass that, backed with the proper alloy, formed a mirror that for the first time gave both sexes a true reflection of their appearance.
One of the most common of modern superstitions is that to break a mirror invites death, or seven years of bad luck. This old folk belief originated with the Romans about the first century C.E. They believed that the health of a person changed every seven years, and as the mirror reflected the health or the appearance of the person, to break a mirror would be to shatter one's health for a period of seven years. Among highly superstitious people the breaking of the mirror came to be looked upon as a death omen. Somehow this superstitious belief has prevailed and still exists even among educated people.