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 that may prevent your eye or eyes from opening in the morning.
• Tearing.
• Sensitivity to light, called photophobia.

When to see a doctor

There are serious eye conditions that can cause eye redness. These conditions may cause eye pain, a feeling that something is stuck in your eye, blurred vision and light sensitivity. If you experience these symptoms, seek urgent care.

People who wear contact lenses need to stop wearing their contacts as soon as pink eye symptoms begin. If your symptoms don't start to get better within 12 to 24 hours, make an appointment with your eye doctor to make sure you don't have a more serious eye infection related to contact lens use.

Causes of pink eye include:

• Viruses.
• Bacteria.
• Allergies.
• A chemical splash in the eye.
• A foreign object in the eye.
• In newborns, a blocked tear duct.

Viral and bacterial conjunctivitis

Most cases of pink eye are caused by adenovirus but also can be caused by other viruses, including herpes simplex virus and varicella-zoster virus.

Both viral and bacterial conjunctivitis can occur along with colds or symptoms of a respiratory infection, such as a sore throat. Wearing contact lenses that aren't cleaned properly or aren't your own can cause bacterial conjunctivitis.

Both types are very contagious. They are spread through direct or indirect contact with the liquid that drains from the eye of someone who's infected. One or both eyes may be affected.

Allergic conjunctivitis

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). IgE triggers special 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 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 eye drops. Allergic conjunctivitis is not contagious.

Conjunctivitis resulting from irritation

Irritation from a chemical splash or foreign object in your eye also is associated with conjunctivitis. Sometimes flushing and cleaning the eye to wash out the chemical or object causes redness and irritation. Symptoms, which may include watery eyes and a mucous discharge, usually clear up on their own within about a day.

If flushing doesn't resolve the symptoms, or if the chemical is a caustic one such as lye, see your health care provider or eye specialist as soon as possible. A chemical splash into the eye can cause permanent eye damage. Ongoing symptoms could indicate that you still have the foreign body in your eye. Or you also could have a scratch on the cornea or the membrane covering the eyeball, called the conjunctiva.

Risk factors for pink eye include:

• Exposure to someone infected with the viral or bacterial form of conjunctivitis.
• Exposure to something you're allergic to, for allergic 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 health care provider can reduce the risk of complications. See your provider if you have:

• Eye pain.
• A feeling that something is stuck in your eye.
• Blurred vision.
• Light sensitivity.

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 old eye cosmetics, such as mascara.
• Don't share eye cosmetics or personal eye care items.

Keep in mind that pink eye is no more contagious than the common cold. It's okay to return to work, school or child care if you're able to practice good hygiene and avoid close contact. However, if work, school or child care involves close contact with others it may be best to stay home until you or your child's symptoms clear up.

Preventing pink eye in newborns

Newborns' eyes are susceptible to bacteria present in the mother's birth canal. These bacteria often cause no symptoms in the mother. In some cases, these bacteria can cause infants to develop a serious form of conjunctivitis known as ophthalmia neonatorum, which needs immediate treatment 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.

In most cases, your health care provider can diagnose pink eye by asking about your recent health history and symptoms and examining your eyes.

Rarely, your provider may take a sample of the liquid that drains from your eye for laboratory analysis, called a culture. A culture may be needed if your symptoms are severe or if your provider suspects a high-risk cause, such as:

• A foreign body in your eye.
• A serious bacterial infection.
• A sexually transmitted infection.

Pink eye treatment is usually focused on symptom relief. Your provider may recommend:

• Using artificial tears.
• Cleaning your eyelids with a wet cloth.
• Applying cold or warm compresses several times daily.

If you wear contact lenses, you'll be advised to stop wearing them until treatment is complete. Your provider will likely recommend that you throw out soft contacts you've already worn.

Disinfect hard lenses overnight before you reuse them. Ask your provider if you should discard and replace your contact lens accessories, such as the lens case used before or during the illness. Also replace any eye makeup used before your illness.

In most cases, you won't need antibiotic eye drops. Since conjunctivitis is usually viral, antibiotics won't help. They may even cause harm by reducing their effectiveness in the future or causing a medicine reaction. Instead, the virus needs time to run its course. This typically takes around 2 to 3 weeks.

Viral conjunctivitis often begins in one eye and then infects the other eye within a few days. Your symptoms should gradually clear on their own.

Antiviral medicines may be an option if your viral conjunctivitis is caused by the herpes simplex virus.

Treatment for allergic conjunctivitis

If the irritation is allergic conjunctivitis, your health care provider may prescribe one of many different types of eye drops for people with allergies. These may include medicines that help control allergic reactions, such as antihistamines and mast cell stabilizers. Or your provider may recommend medicines to help control inflammation, such as decongestants, steroids and anti-inflammatory drops.

Nonprescription versions of these medicines also may be effective. Ask your provider about the best option for you.

You might reduce the severity of your allergic conjunctivitis symptoms by avoiding whatever causes your allergies.

To help you cope with the 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. Generally, a cool water compress will feel the most soothing, but you also can use a warm compress if that feels better to you. 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 eye drops. Nonprescription eye drops called artificial tears may relieve symptoms. Some eyedrops contain antihistamines or other medicines 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 health care provider 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.

Start by seeing your regular health care provider if you have any eye-related signs or symptoms that worry you. If your symptoms persist or get worse, despite treatment, your provider may refer you to an eye specialist (ophthalmologist).

Because appointments can be brief, and because there's often a lot of ground to cover, it's a good idea to be well prepared for your appointment. Here's some information to help you get ready for your appointment and what to expect.

What you can do

• Be aware of any pre-appointment restrictions. At the time you make the appointment, be sure to ask if there's anything you need to do in advance, such as stop wearing contact lenses or refrain from using eye drops.
• Write down any symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.
• Make a list of all medications, vitamins or supplements that you're taking.
• Write down questions to ask during your appointment.

Your time with your doctor is limited, so preparing a list of questions can help you make the most of your time together. List your questions from most important to least important in case time runs out. For pink eye, some basic questions to ask include:

• What's the most likely cause of my symptoms?
• What kinds of tests do I need?
• What treatments are available?
• How long will I be contagious after starting treatment?
• Is there a generic alternative to the medicine you're prescribing me?
• Are there any brochures or other printed material that I can take with me? What websites do you recommend?
• Do I need to come back for a follow-up visit?

In addition to the questions that you've prepared to ask, don't hesitate to ask additional questions.

What to expect from your doctor

Your provider is likely to ask you a number of questions. Being ready to answer them may allow time later to cover points you want to address. You may be asked:

• When did you begin experiencing symptoms?
• Have your symptoms been continuous or occasional?
• How severe are your symptoms?
• Does anything improve your symptoms?
• What, if anything, appears to worsen your symptoms?
• Do your symptoms affect one eye or both eyes?
• Do you use contact lenses?
• How do you clean your contact lenses?
• How often do you replace your contact lens storage case?
• Have you had close contact with anyone who has pink eye or cold or flu symptoms?

What you can do in the meantime

Stop using contact lenses until you can see your provider. Wash your hands frequently to lessen the chance of infecting other people. Don't share towels with other people for the same reason.