A sty (hordeolum) is a red, painful lump on the edge or inside of your eyelid that may look like a boil or a pimple. Usually a sty is filled with pus. As it swells in size, the sty may make it difficult for you to see clearly because you can’t fully open your eye.
More than one sty can occur at a time, leading to a generalized inflammation of your eyelid — a condition known as blepharitis. Fortunately, most sties disappear in just a few days. In the meantime, you may be able to relieve the pain or discomfort of a sty with simple self-care treatments.
The cause of a sty is a bacterial infection, usually staphylococcus. Usually the bacterial infection develops near the root (follicle) of an eyelash. You may have more than one sty at a time or several in succession.
Sties aren’t especially contagious, but may develop due to poor hygiene habits. Sties may also develop if you use expired cosmetics or leave eye makeup on overnight. Contact lens wearers may develop sties if they don’t thoroughly wash their hands and disinfect their contact lenses before putting their contacts in. Chronic blepharitis may also be a cause of sty formation. Treatment of the chronic blepharitis may help prevent sty recurrence.
Most sties eventually fill with pus and then rupture. The release of pus relieves one major symptom of sties — pain. Usually the sty then disappears.
Symptoms of sties include:
- A red lump similar to a boil or a pimple
- Swelling on your eyelid
- Light sensitivity
- A scratchy sensation in your eye
Most sties are harmless to your eye and don’t affect your ability to see clearly. Still, you may want to see your doctor if a sty causes one of the following problems:
- Interferes with your vision
- Appears frequently with successive infections
- Doesn’t disappear on its own
- Doesn’t respond to self-care
- Develops redness or swelling that extends beyond the lid into your face or cheek
If the signs and symptoms of a sty persist or if you’ve had successive infections, your doctor may want to exclude other possible causes. Some conditions exist that are similar to a sty, but require different treatment. For instance a chalazion — a blockage in one of the small glands in the eyelid — can produce swelling similar to that of a sty.
If your doctor confirms you have a sty, he or she can prescribe treatment or recommend ways to relieve your pain or discomfort. If a sty is ruled out, your doctor may refer you to an ophthalmologist for further examination and treatment. An ophthalmologist is a medical doctor who can provide comprehensive eye and vision care.
If your doctor confirms that you have a sty, he or she may prescribe a topical antibiotic cream to apply to your eyelid. To treat a pus-filled sty that won’t rupture or burst on its own, your doctor or ophthalmologist may choose to lance and drain the sty to relieve pain and pressure. Usually sty treatment doesn’t require oral antibiotics unless you have a generalized infection of your eyelid.
Don’t try to squeeze the pus from a sty on your own. To relieve the pain and help a sty come to a point sooner, soak a clean cloth in warm water, wring it out and then apply it as a compress to your eyelid for 10 minutes, four times a day. Once the sty drains on its own, keep the area clean.
To prevent recurrent infections:
- Wash your hands. Keep your hands away from your eyes and practice good hand-washing techniques. If you have children, make sure they know and practice proper hand-washing techniques because they may be more prone to sties.
- Take care with cosmetics. You can help prevent recurrent infections by not using old cosmetics or sharing makeup with anyone.
- Make sure your contact lenses are clean. If you wear contact lenses, wash your hands thoroughly before inserting your contacts and follow your doctor’s advice on disinfecting your contacts.
You may need to take special precautions, such as deliberately cleaning your eyelid, if you have underlying chronic blepharitis.