A stye is caused by an infection of an oil gland or hair follicle on the eyelid, most commonly due to bacteria called Staphylococcus aureus. This infection results when the gland becomes blocked and bacteria multiply, leading to a painful, red lump similar to a pimple. Styes may form on the outer edge of the eyelid (external) or inside the eyelid (internal). Common ways to get a stye include:
- Rubbing or touching the eyes with hands that carry bacteria.
- Poor hygiene, such as not washing hands before touching eyes or improper contact lens care.
- Using old or contaminated eye makeup.
- Skin conditions like rosacea or blepharitis that increase risk.
- Exposure to bacteria from the nose or shared items like pillowcases and towels.
The bacteria can be transferred from the nose to the eye or from contaminated surfaces to the eyelid, causing infection of the oil glands that normally lubricate the eye. Factors like poor nutrition, sleep deprivation, and stress can also contribute to the likelihood of developing a stye. In summary, a stye forms when bacteria infect a blocked oil gland or eyelash follicle on the eyelid, often triggered by touching the eyes with unclean hands or exposure to contaminated items.
