Topic Overview

Pinkeye (also called conjunctivitis) is redness and swelling of the conjunctiva, the mucous membrane that lines the eyelid and eye surface. The lining of the eye is usually clear. If irritation or infection occurs, the lining becomes red and swollen. See pictures of a normal eye and an eye with conjunctivitis.

Pinkeye is very common. It usually is not serious and goes away in 7 to 10 days without medical treatment.

Most cases of pinkeye are caused by:

• Infections caused by viruses or bacteria.
• Dry eyes from lack of tears or exposure to wind and sun.
• Chemicals, fumes, or smoke (chemical conjunctivitis).
• Allergies.

Viral and bacterial pinkeye are contagious and spread very easily. Since most pinkeye is caused by viruses for which there is usually no medical treatment, preventing its spread is important. Poor hand-washing is the main cause of the spread of pinkeye. Sharing an object, such as a washcloth or towel, with a person who has pinkeye can spread the infection. For tips on how to prevent the spread of pinkeye, see the Prevention section of this topic.

Viral pinkeye

Viral pinkeye is often caused by an adenovirus, which is a common respiratory virus that can also cause a sore throat or upper respiratory infection. The herpes virus can also cause viral pinkeye.

Symptoms of viral pinkeye include:

• Redness in the white of the eye.
• Swelling of the eyelids.
• Itching or burning feeling of the eyelids.
• Swollen and tender areas in front of the ears.
• A lot of tearing.
• Clear or slightly thick, whitish drainage.

Viral pinkeye symptoms usually last 5 to 7 days but may last up to 3 weeks and can become ongoing or chronic.

Pinkeye may be more serious if you:

• Have a condition that decreases your body's ability to fight infection (impaired immune system).
• Have vision in only one eye.
• Wear contact lenses.

If the pinkeye is caused by a virus, the person can usually return to day care, school, or work when symptoms begin to improve, typically in 3 to 5 days. Medicines are not usually used to treat viral pinkeye, so it is important to prevent the spread of the infection. Pinkeye caused by a herpes virus, which is rare, can be treated with an antiviral medicine. Home treatment of viral pinkeye symptoms can help you feel more comfortable while the infection goes away.

Bacterial pinkeye

An infection may develop when bacteria enter the eye or the area around the eye. Some common infections that cause pinkeye include:

• Staph infection.
• Haemophilus influenzae type b (Hib).
• Cat-scratch disease.
• Gonorrhea.

Symptoms of bacterial pinkeye include:

• Redness in the white of the eye.
• Gray or yellow drainage from the eye. This drainage may cause the eyelashes to stick together.
• Mild pain.
• Swelling of the upper eyelid, which may make the lid appear to droop (pseudoptosis).

Bacterial pinkeye may cause more drainage than viral pinkeye. Bacterial infections usually last 7 to 10 days without antibiotic treatment and 2 to 4 days with antibiotic treatment. The person can usually return to day care, school, or work 24 hours after an antibiotic has been started if symptoms have improved. Prescription antibiotic treatment usually kills the bacteria that cause pinkeye.

Red eye

Red eye is a more general term that includes not only pinkeye but also many other problems that cause redness on or around the eye, not just the lining. Pinkeye is the main cause of red eye. Red eye has other causes, including:

• Foreign bodies, such as metal or insects. For more information, go to the topic Objects in the Eye.
• Scrapes, sores, or injury to or infection of deeper parts of the eye (for example, uveitis, iritis, or keratitis). For more information, go to the topic Eye Injuries.
• Glaucoma. For more information, go to the topics Eye Problems, Noninjury or Glaucoma.
• Infection of the eye socket and areas around the eye. For more information, go to the topic Eye Problems, Noninjury.

Swollen, red eyelids may also be caused by styes, a lump called a chalazion, inflammation of the eyelid (blepharitis), or lack of tears (dry eyes). For more information, go to the topics Styes and Chalazia or Eyelid Problems (Blepharitis).

Use the Check Your Symptoms section to decide if and when you should see a doctor.