What causes styes in your eyes?

These usually represent n infection by various strains of the germ staphylococcus.

Styes are either acute infections in the oil-secreting glands of the eyelids (hordeolum) which occur when bacteria are trapped, or chronic infections (chalazion) that are a granulomatous reaction to oils that are unable to get to the surface and drain. Hot compresses and antibiotics can help the hordeola come to a head and drain, but minor surgery is often required to clear a chalazion.