Stye. Close-up of a patient's left eye, showing a stye (hordeolum) on the edge of the upper eyelid. The stye is swollen, red and inflamed, and appears slightly yellow in the centre. Styes are pus- filled abscesses that grow on the eyelid. They are caused by bacterial infection of the gland at the base of an eyelash, and typically form near the inner corner of an eye. Treatment includes bathing the stye in warm water, which can help to dis- charge the pus, and removing the infected eyelash. Antibiotic drugs can help to prevent a recurrence.