Stye bacterial eye infection in a 44-year-old man. The style is the white rounded area at centre on the patient's lower eyelid. This is a common condition caused by bacterial infection, in the majority of cases by staphylococci bacteria. The bacteria gain access via hair follicles or sebaceous glands, or through minor abrasions to the skin. The symptoms include inflammation and pain. Here, the infection is at an advanced stage, with pus present.