Styes, also known as hordeolums, are common eye conditions characterized by the formation of a painful and swollen lump on the eyelid. They typically appear as red, tender bumps near the edge of the eyelid and can occur on either the upper or lower eyelid. Styes are usually caused by a bacterial infection, most commonly by the bacteria Staphylococcus aureus.

The development of styes is often accompanied by symptoms such as eye irritation, sensitivity to light, tearing, and a feeling of a foreign body in the eye. They can be classified as either external or internal styes, depending on the location of the infection. External styes occur when an infection develops in the hair follicles at the base of the eyelashes, while internal styes form when an infection affects the oil glands within the eyelid.

Styes may resolve on their own within a few days or weeks as the body's immune system fights off the infection. However, home remedies such as warm compresses can help reduce pain and promote healing. In some cases, a stye may drain pus on its own. It is important to avoid squeezing or popping a stye, as this can spread the infection.

If the stye persists or worsens, medical intervention may be necessary. An eye doctor may prescribe antibiotic ointments or oral antibiotics to treat the infection more effectively. In some instances, a doctor may need to lance and drain the stye using a sterile needle or scalpel. Overall, proper eyelid hygiene, such as regularly cleaning the eyelids, can help prevent the formation of styes.