Saint Lucia, also known as Saint Lucy, is venerated as a Catholic/Anglican/Lutheran saint, though her legend is most likely apocryphal and not based on a real historical figure. She's one of the church's virgin martyrs. In one version of the story, a young suitor told her how lovely her eyes were, so Lucia plucked them out so that she could better devote herself to the monastic life without distractions. Thus, she is the patron saint of the blind. Appropriately, her name comes from the Latin word for "light."
I do not know why the French named their beautiful Caribbean island in the Lesser Antilles after this saint.
Although revered in many countries, Saint Lucia is hugely popular in Sweden. In Swedish tradition, at the first crow of the rooster on St. Lucia's Day, a beautiful young woman of the household would rise and dress in a white robe tied with a red sash. She would wear on her head a crown of twigs, into which nine white candles were placed and lit. This is the popular representation of St. Lucia. The young woman representing the saint would wake up the household with singing and a sweet drink (coffee, when it was available). The household then sat down to a candlelit breakfast.
Lucia is also venerated in Sicily. An effigy of the saint is carried through the street in procession; she's depicted as carrying a dish containing her eyes. At the end of the procession, there's a large bonfire.
The extensive use of candles and fire on St. Lucia's Day links the celebration to other traditional Winter Solstice celebrations, including Hanukkah, which prescribe light for the shortest, darkest days of the year.
In some parts of central Europe, St. Lucia serves the function of Frigga and her folkloric descendants, punishing young people who've been naughty or neglectful and rewarding the good. Some regions put Lucia in charge of gifts for girls, while St. Nicholas, whose feast day is observed December 6th, serves this function for boys.
Eves often have special significance in Winter Solstice celebrations, owing to the ancient custom of reckoning days from sunset, still observed by Jews and Muslims. St. Lucia's Eve is also associated with witchcraft. Some observers go around saying special blessings to protect themselves from wayward magic. In other places, St. Lucia's Eve is used for divination, often of the "whom will I marry?" type practiced on St. Mark's Eve, St. John's Eve and All Hallows Eve.
Denmark has a particularly lovely prayer for this occasion:
"Sweet St. Lucy, let me know;
Whose cloth I shall lay,
Whose bed I shall make,
Whose child I shall bear,
Whose darling I shall be,
Whose arms I shall sleep in."
Again I refer to Christmas Customs and Traditions: Their History and Significance by Clement A. Miles.
