Why is my left eye twitching, and what superstitions are associated with this phenomenon?

Eye twitching, also known as myokymia, is usually caused by stress, fatigue, or caffeine intake. Superstitions suggest that left eye twitching may indicate bad luck or impending misfortune in some cultures, while others believe it signifies good news or a forthcoming visitor. However, these beliefs have no scientific basis and should not be taken seriously.