Conjunctivitis, often called "pink eye," is an inflammation (redness) of the conjunctiva, the clear tissue that lines the inside surface of your eyelid and outer coating of your eye. This tissue helps keep your eyelid and eyeball moist.
Pink eye can occur in one or both eyes. Pink eye that occurs in both eyes tends to be caused by a virus.
Pink eye is one of the most common eye infections in children and adults. Between three and six million cases of pink eye occur in the U.S. each year.
Technically, the pink or reddish color of pink eye happens when the blood vessels in the membrane covering your eye (the conjunctiva) becomes inflamed, making them more visible. This inflammation is caused by:
Pink eye that is caused by bacteria or viruses are very easily spread from person to person (contagious). If you get pink eye from bacteria, you can spread pink eye while you have symptoms or until about 24 to 48 hours after starting antibiotic treatment. If you get pink eye from a virus, you can spread it for as long as you have symptoms and even before you develop symptoms. This could be for several days. Pink eye caused by an allergy is not contagious.
Pink eye is spread:
Symptoms of pink eye include:
Your ophthalmologist or pediatrician will examine you or your child’s eyes. An acuity test (eye chart test) may be done to see if vision has been affected. Diagnosis of pink eye can usually be made based on symptoms and health history. Rarely are other tests ordered. However, if bacteria are thought to be the cause or if the infection is severe, your healthcare provider may send a sample (cotton swab) of the secretions around your eye to a lab to identify the specific organism.
Although the symptoms of pink eye can be the same regardless of cause, there are a few signs your healthcare provider considers to help determine if pink eye is a bacterial or viral infection. These are:
Treatment of pink eye depends on its cause.
Pink eye caused by bacteria
If your pink eye is caused by bacteria, you’ll likely be given a prescription for antibiotics (eye drops, ointments or pills). You may find it difficult to apply ointment to your or your child’s eye. Don’t worry. If the ointment gets as far as the eyelashes, it will most likely melt and enter the eye.
The infection should improve within a week. Take the medicine as instructed by your healthcare provider, even if the symptoms go away.
Pink eye caused by viruses
Antibiotics can’t treat pink eye caused by a virus. Just as a cold must run its course, so must this form of pink eye, which will last from four to seven days but can take up to 14 days to fully resolve. In the meantime, apply a cold compress or use artificial tears several times a day to help relieve symptoms.
Pink eye caused by irritating substances
If your eyes are irritated after a substance gets into them, rinse your eyes with a gentle stream of warm water for five minutes. Avoid further exposure to the irritating substances. Your eyes should begin to improve within four hours after rinsing them. If they don’t, call your doctor. If the substance in your eyes is a strong acid or alkaline chemical (such as drain cleaner), rinse your eyes with water and call your doctor immediately.
Pink eye caused by allergies
Allergic conjunctivitis is treated with prescription or over-the-counter eye drops that contain either antihistamines to control allergic reactions or anti-inflammatory drugs such as steroids or decongestants. You can relieve symptoms temporarily – by applying a cold compress on closed eyes – or permanently by avoiding the allergens that are causing your symptoms.
Other causes of pink eye
Less commonly, bacteria that causes sexually transmitted infections can cause pink eye. This route of infection occurs from hand-to-eye transmission of genital fluids. If you think you were exposed to a sexually transmitted infection, tell your doctor. Bacterial pink eye is treated with antibiotics; viral pink eye is treated with antiviral medications.
Newborn babies can develop a serious type of conjunctivitis if they are delivered vaginally by women with sexually transmitted infections. The bacteria are picked up by the newborn during the delivery process. The bacteria can cause loss of sight. It’s standard practice in U.S. hospitals is to apply an antibiotic ointment to the eyes of every newborn to help prevent this eye infection.
Autoimmune conditions — diseases in which your own immune system overreacts — are also a rare cause of pink eye. If you have a family history or other reason to suspect an autoimmune disease, discuss this with your doctor.
Mild cases of pink eye usually don’t require treatment and clear on their own within a few days (for bacterial infections) to about 14 days (for viral infections). The relief methods listed in a question below can provide comfort. Pink eye caused by a virus don’t require treatment unless it’s caused by herpes simplex virus, varicella-zoster virus (chickenpox/shingles) or sexually transmitted diseases. In these cases, an antiviral medication may be prescribed. Antibiotics for pink eye caused by bacteria reduce the length of your symptoms and the amount of time you are contagious.
If you or your child has bacterial or viral pink eye, your healthcare provider may recommend staying home from work, school or daycare until you are no longer contagious. Check with your doctor to find out how long that may be. Typically, you’re less likely to spread the infection if you’ve been on antibiotics for 24 hours or no longer have symptoms.
Following good general hygiene and eye care practices can also help prevent the spread of pink eye. These practices include:
Since many cases of pink eye are mild, you can often get by with relieving symptoms at home until the condition passes. Applying nonprescription “artificial tears” eye drops may help relieve itching and burning from irritating substances.
Note: Other types of eye drops may irritate the eyes, so don’t use them. Avoid eye drops that have medication to “get the red out.” Also, do not use the same bottle of drops in the other eye if it is not infected.
Other measures to take to relieve the symptoms of pink eye (conjunctivitis) include:
Pink eye is highly contagious if it is caused by a bacterial or viral infection. The good news is that it is not usually a serious condition. You or your child can return to daycare, school or work as soon as the infection goes away, which might be a few days to one to two weeks depending if your case is mild or more severe. If pink eye is caused by allergies, it is not contagious and you can return to normal activities at any time.
Most cases of mild to moderate pink eye clear on their own without treatment. Treatment is often needed if pink eye is severe and can shorten the amount of time you feel symptoms and can spread the condition to others.
Call your healthcare provider or seek medical care right away if you experience:
Herpes, one of many possible causes of pink eye, is a serious infection. If not treated, vision loss and scarring of the eye are possible.
Most cases of pink eye are not associated with worrisome effects. However, these symptoms can be a sign of a serious problem, such as an ulcer, which can result in permanent vision loss. Never hesitate to call your healthcare provider if you have any concerns. It’s always better to be safe than sorry.
Pink eye can reoccur, especially if you have allergy-related pink eye. Every time you’re in contact with the allergen (a substance that triggers allergies), your eyes may react.
If you have bacterial or viral pink eye, you can also accidentally re-infect yourself. To avoid coming down with another case of contagious pink eye, consider the following measures:
You can usually go back to daycare, school or work as soon as your symptoms go away. Generally this might be as soon as 24 hours after antibiotic treatment of bacterial infection and between two days and seven days after viral infection. You or your child’s eye should be clear of yellowish discharge or any crusting on eyelashes or in the corners of the eyes. Eyes should also be cleared of the pink color. Be sure to check with your healthcare provider and facilities about when it is safe to return or for any special “return to” requirements. If your pink eye was caused by an allergy, you do not need to stay home.
Both pink eye and a stye share some common symptoms, including redness, sensitivity to light and crusting along the eyelids. However, these two conditions are different and have different causes.
A stye is a red, painful bump that forms either on or inside the eyelid near the edge of the eyelashes. Pink eye is an inflammation of the lining of the inside surface of the eyelid and outer coating of the eye. Pink eye doesn’t cause bumps in your eyelid or around your eye.
Styes are caused by an infection in the oil glands on your eyelid. Pink eye is caused by viruses, bacteria, allergens and other causes different than what causes styes.
Final thoughts. . .
Pink eye usually isn’t serious and the good news is it’s highly treatable and preventable. Unless your case of pink is severe, pink eye can heal on its own without treatment. Treatment of bacterial or viral pink eye, however, can shorten the amount of time you or your child will have symptoms and are contagious. While healing, you can apply a cool (or warm) compress to relieve discomfort. The best thing you can do is take the necessary steps to avoid spreading pink eye to others or getting a repeat case of it. If you have any questions or concerns, always call your healthcare provider.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or healthcare provider. Please consult your healthcare provider for advice about a specific medical condition. This document was last reviewed on: 04/10/2020