Conjunctivitis (Pink Eye)

An inflammation of the conjunctiva, the thin, transparent layer that covers the inner eyelid and the white portion at the front of the eye (the sclera).

Last Updated: March 11, 2023

Video: What is pink eye? | Dr. Trevor Miranda

What is Conjunctivitis or Pink Eye?

Conjunctivitis – commonly known as Pink Eye – is an inflammation of the conjunctiva, the thin, transparent layer that covers the inner eyelid and the white portion at the front of the eye (the sclera).  An irritation will cause the blood vessels contained in the conjunctiva to dilate, which is what causes red or bloodshot eyes. It is often associated with either watery discharge or sticky, mucous discharge). Although conjunctivitis is common among children and may be caused by a minor infection, all ages may be affected.  It is important to note that some forms of conjunctivitis may develop into a more serious problem if not diagnosed and treated properly.

What Causes Conjunctivitis?

There are 3 categories of conjunctivitis which differ in offending agent:

1. Infectious Conjunctivitis

  • Bacterial Conjunctivitis can be contracted from direct contact with bacteria associated with unclean hands, bacteria transmitted from insects and contaminated eye makeup or facial lotions. This type of conjunctivitis is contagious. Some forms are self-limiting, minor and can be resolved a bit faster with antibiotic treatment.  Some forms (gonorrhea) are more severe.
  • Viral Conjunctivitis is most commonly caused by viruses associated with the common cold. It is highly contagious and can be contracted following an upper respiratory infection through the body’s own mucous membranes, which connect the lungs, throat, nose and eyes, or through airborne exposure to the coughing or sneezing of someone with an upper respiratory tract infection. Typically when this type of virus occurs in one eye, it will quickly spread to the other. This spread also happens with bacterial conjunctivitis.

2. Allergic Conjunctivitis:

  • Allergic Conjunctivitis is caused by direct contact with eye irritants in those who are susceptible. This type of conjunctivitis can be seasonal (pollen, ragweed, grass, etc), or it may occur year-round (dust, fabrics, animal dander, etc).  This form of conjunctivitis is not contagious.

3. Chemical Conjunctivitis:

  • Chemical Conjunctivitis is caused by exposure to irritants such as air pollution, noxious chemicals or chlorine in a swimming pool. This form of conjunctivitis is not contagious.

Symptoms of Pink Eye

Those who have contracted conjunctivitis may experience some of the following symptoms:

  • Pink discolouration to the whites of the eye(s)
  • Itching or burning sensation
  • Swollen eyelid(s)
  • Sensitivity to light
  • Excessive tearing
  • Sticky yellow discharge from the eye(s) or watery discharge, or stringy discharge

Treatment of Pink Eye

The treatment for pink eye depends on the type that you have contracted:

1. Infectious Conjunctivitis:

Bacterial conjunctivitis can be treated with antibiotic eye drops or ointments prescribed by your eye doctor.

Viral conjunctivitis, unlike bacterial infections, cannot be treated with antibiotics. This form of conjunctivitis is self-limited, which means that the infection will go away on its own anywhere between 7 days to several weeks duration.

Some doctors of optometry use off-label treatment for viral conjunctivitis to clear away as much virus as possible in the eye while the immune system has a chance to kick in and help stop the spread of the virus (see Betadine treatment for info). Sometimes (steroid) eye drops are used to prevent scarring of cornea.

Artificial tears can be used frequently, and applying a wet, cold washcloth to the infected eye to relieve discomfort from the symptoms. (NOTE: Due to the highly contagious nature of this type of pink eye, be very careful not to share used cloths!) – frequent handwashing, avoid touching eyes, sharing towels, etc. are important. Patients are also advised to stay away from school/work for a full 2 weeks from onset of viral conjunctivitis as it is contagious during this period (10-12 days).

2. Allergic Conjunctivitis:

Allergy medications (antihistamine) can help provide relief, shorten the length, and sometimes even prevent the onset of allergic conjunctivitis. If you suffer from seasonal allergies, speak with your doctor about beginning these medications early in order to get ahead of the symptoms.

3. Chemical Conjunctivitis

The treatment of chemical conjunctivitis depends on the degree of exposure. For minor irritation such as chlorine from swimming in a pool, carefully rinse the eyes and consider purchasing a good pair of goggle for future activities. More acute chemical exposure may be a medical emergency and call for immediate medical attention.

Tips to Prevent Pink Eye

These are especially true for viral forms, but also make sense for bacterial forms. With a better understanding of the different forms of conjunctivitis, here are some easy tips to help reduce the risk of contracting the very contagious viral conjunctivitis:

  • Wash your hands thoroughly and frequently with soap and warm water. 
  • Carry small bottles of hand sanitizer(such a Purell) when in public spaces, especially if you have spent time in a school. 
  • Never (ever) share costume contact lenses or their cases.  
  • If you are suffering from cold or flu-like symptoms, avoid rubbing your eyes. 
  • Do not share personal items such as towels, washcloths, tissues or eye makeup and eye makeup brushes. 
  • Wipe down surfaces of frequently used areas or items with antibacterial cleaners. (Door knobs, telephones, counter tops, faucet handles, television remotes, etc) 
  • If your child has Viral Pink Eye, keep them home from school until the contagious stage has passed. (see above)

If you have already contracted Viral Pink Eye, here are a few tips to prevent spreading the infection between eyes and to others:

  • Avoid touching or rubbing your eyes. 
  • Wash your hands with warm water and soap after applying eye drops or ointment.
  • Do not use the same eye dropper or cloth between infected and non-infected eyes when applying eye drops or ointment. 
  • Wash discharge from around the eye several times a day and dispose of cotton ball or tissue. (If a towel has been used, be very careful that is does not contaminate surrounding areas and wash with hot water and detergent.)
  • Frequently wash pillow cases, sheets, blankets and towels with hot water and detergent. 
  • Throw away and replace eye makeup, face make up, make up brushes, contact lenses and cases that were used while infected. 

IMPORTANT: Having a pink or red eye can be the symptom of many eye problems beyond conjunctivitis – some of which can damage your vision if not treated appropriately. If you or your child experiences this change of colour to the whites of their eyes (or pain, light sensitivity), see a Doctor of Optometry right away.