The medical term for eyelid stye is blepharitis or mydriasis, which is an inflammatory reaction caused by an acute inflammatory response to infection of the eyelid glands by septic bacteria, primarily Staphylococcus aureus, and especially Staphylococcus aureus. There are several different glands in the eyelid. If the inflammation is caused by infection of the hair follicles of the eyelashes or their accessory sebaceous glands, as well as the metaplastic sweat glands, it is called exophthalmos, or exophthalmos; if it is an infection of the lid glands, it is called endophthalmos. Treatment of blepharitis or mydriasis is mainly local or systemic anti-infective and anti-inflammatory.