What is it?
Pink eye (conjunctivitis) is an inflammation or infection of the transparent membrane (conjunctiva) that lines your eyelid and part of your eyeball. Inflammation causes small blood vessels in the conjunctiva to become more prominent, which is what causes the pink or red cast to the whites of your eyes.
The cause of pink eye is commonly a bacterial or viral infection, an allergic reaction or — in babies — an incompletely opened tear duct.
Though the inflammation of pink eye can be irritating, it rarely affects your vision. If you suspect pink eye, you can take steps to ease your discomfort. But because pink eye can be contagious, early diagnosis and treatment is best to help limit its spread.
The most common pink eye symptoms include:
- Redness in one or both eyes
- Itchiness in one or both eyes
- A gritty feeling in one or both eyes
- A discharge in one or both eyes that forms a crust during the night
Causes of pink eye include:
- A chemical splash in the eye
- A foreign object in the eye
- In newborns, a blocked tear duct
Viral and bacterial conjunctivitis
Viral conjunctivitis and bacterial conjunctivitis may affect one or both eyes. Viral conjunctivitis usually produces a watery discharge. Bacterial conjunctivitis often produces a thicker, yellow-green discharge. Both viral and bacterial conjunctivitis can be associated with colds or with symptoms of a respiratory infection, such as a sore throat.
Both viral and bacterial types are very contagious. Adults and children alike can develop both of these types of pink eye. However, bacterial conjunctivitis is more common in children than it is in adults.
Allergic conjunctivitis affects both eyes and is a response to an allergy-causing substance such as pollen. In response to allergens, your body produces an antibody called immunoglobulin E (IgE). This antibody triggers special cells called mast cells in the mucous lining of your eyes and airways to release inflammatory substances, including histamines. Your body's release of histamine can produce a number of allergy signs and symptoms, including red or pink eyes.
If you have allergic conjunctivitis, you may experience intense itching, tearing and inflammation of the eyes — as well as sneezing and watery nasal discharge. Most allergic conjunctivitis can be controlled with allergy eyedrops.
Conjunctivitis resulting from irritation
Irritation from a chemical splash or foreign object in your eye is also associated with conjunctivitis. Sometimes, flushing and cleaning the eye to rid it of the chemical or object causes redness and irritation. Signs and symptoms, which may include watery eyes and a mucous discharge, usually clear up on their own within about a day.
Risk factors for pink eye include:
- Exposure to an allergen for allergic conjunctivitis
- Exposure to someone infected with the viral or bacterial form of conjunctivitis
- Using contact lenses, especially extended-wear lenses
In both children and adults, pink eye can cause inflammation in the cornea that can affect vision. Prompt evaluation and treatment by your doctor can reduce the risk of complications.
To determine whether you have pink eye, your doctor may examine your eyes. Your doctor may also take a sample of eye secretions from your conjunctiva for laboratory analysis to determine which form of infection you have and how best to treat it.
Treatments and drugs
Treatment for bacterial conjunctivitis
If your infection is bacterial, your doctor may prescribe antibiotic eyedrops as pink eye treatment, and the infection should go away within several days. Antibiotic eye ointment, in place of eyedrops, is sometimes prescribed for treating bacterial pink eye in children. An ointment is often easier to administer to an infant or young child than are eyedrops, though the ointment may blur vision for up to 20 minutes after application. With either form of medication, expect signs and symptoms to subside within a few days. Follow your doctor's instructions and use the antibiotics until your prescription runs out, to prevent recurrence of the infection.
Treatment for viral conjunctivitis
There is no treatment for most cases of viral conjunctivitis. Instead, the virus needs time to run its course — up to two or three weeks. Viral conjunctivitis often begins in one eye and then infects the other eye within a few days. Your signs and symptoms should gradually clear on their own.
Antiviral medications may be an option if your doctor determines that your viral conjunctivitis is caused by the herpes simplex virus.
Treatment for allergic conjunctivitis
If the irritation is allergic conjunctivitis, your doctor may prescribe one of many different types of eyedrops for people with allergies. These may include antihistamines, decongestants, mast cell stabilizers, steroids and anti-inflammatory drops. You may also reduce the severity of your of allergic conjunctivitis symptoms by avoiding whatever causes your allergies, when possible.
To help you cope with the signs and symptoms of pink eye until it goes away, try to:
- Apply a compress to your eyes. To make a compress, soak a clean, lint-free cloth in water and wring it out before applying it gently to your closed eyelids. A cool water compress may help relieve allergic conjunctivitis. If you have bacterial or viral conjunctivitis, you may prefer a warm compress. If pink eye affects only one eye, don't touch both eyes with the same cloth. This reduces the risk of spreading pink eye from one eye to the other.
- Try eyedrops. Over-the-counter eyedrops called artificial tears may relieve symptoms. Some eyedrops contain antihistamines or other medications that can be helpful for people with allergic conjunctivitis.
- Stop wearing contact lenses. If you wear contact lenses, you may need to stop wearing them until your eyes feel better. How long you'll need to go without contact lenses depends on what's causing your conjunctivitis. Ask your doctor whether you should throw away your disposable contacts, as well as your cleaning solution and lens case. If your lenses aren't disposable, clean them thoroughly before reusing them.
Preventing the spread of pink eye
Practice good hygiene to control the spread of pink eye. For instance:
- Don't touch your eyes with your hands.
- Wash your hands often.
- Use a clean towel and washcloth daily.
- Don't share towels or washcloths.
- Change your pillowcases often.
- Throw away your eye cosmetics, such as mascara.
- Don't share eye cosmetics or personal eye-care items.
Although pink eye symptoms may resolve in three or four days, children with viral conjunctivitis may be contagious for a week or more. Children may return to school when they no longer experience tearing and matted eyes.
If your child has bacterial conjunctivitis, keep him or her away from school until after treatment is started. Most schools and child care facilities require that your child wait at least 24 hours after starting treatment before returning to school or child care. Check with your doctor if you have any questions about when your child can return to school or child care.
Preventing pink eye in newborns
Newborns' eyes are susceptible to bacteria normally present in the mother's birth canal. These bacteria cause no symptoms in the mother. In rare cases, these bacteria can cause infants to develop a serious form of conjunctivitis known as ophthalmia neonatorum, which needs treatment without delay to preserve sight. That's why shortly after birth, an antibiotic ointment is applied to every newborn's eyes. The ointment helps prevent eye infection.