Conjunctivitis, commonly known as "pink eye," is an inflammation of the membrane (conjunctiva) that covers the eye and lines the inner surface of the eyelid. There are four main causes of conjunctivitis.

One cause involves the introduction of either bacterial or viral microorganisms into the eye. These may be transmitted to the eye by contaminated hands, washcloths or towels, cosmetics (particularly eye makeup), false eyelashes or extended wear contacts.

Minor conjunctivitis can accompany a viral cold or flu. Although bacterial and some of the viral infections (particularly herpes) are not very common, they are potentially serious. Both types of infection are contagious.

Irritants are another cause of conjunctivitis. Offenders of this type include air pollutants, smoke, soap, hairspray, makeup, chlorine, cleaning fluids, etc.

Seasonal allergic response to grass and other pollens can cause some individuals to acquire conjunctivitis.

Pink eye may be more serious if you have a condition that decreases your ability to fight infection (impaired immune system), and/or vision in only one eye or you wear contact lenses.


Various combinations of the following symptoms may be present: itching, redness, sensitivity to light, feeling as if something is in the eye, swelling of the lids and/or discharge from the eyes. The consistency of possible discharge may range from watery to pus-like, depending on the specific cause of the conjunctivitis. Vision may be affected from the increase in tear production.


It usually takes a few days to two weeks to clear most types of conjunctivitis. Conjunctivitis due to an allergy may continue as long as the offending pollen is present. Under such conditions, symptoms are likely to recur each year.


Diagnosis consists of physical examination of the eye by the clinician. Cultures are not necessary for the initial diagnosis, but may be needed if the initial treatment does not resolve infection.


Treatment varies depending on the cause. Medications in the form of ointments, drops or pills may be recommended to help kill the germ infecting the eye, relieve allergic symptoms and decrease discomfort. In the case of conjunctivitis due to a viral cold or flu, the practitioner may recommend that you be patient and let it run its course.

Other measures that should be followed


Although many kinds of conjunctivitis are hard to prevent, there are measures that can be taken to decrease your risk of reacquiring or spreading it to someone else. These are listed below:


If any of the following problems should occur, notify your clinician:

Directions for using eye drops or ointment

  1. Wash your hands before touching your eyes or your medications.Image depicting finger pulling down the lower eyelid to allow drops.
  2. Gently, pull your lower lid down with your finger.
  3. Look up toward the ceiling.
  4. To instill drops: Drop medicine inside center of your lower lid. Do not drop it on your eyeball. Close your eyes gently without squeezing the lids shut. Blink to distribute medication over the eye. To instill ointment: starting in the corner of your eye closest to the nose, squeeze a thin ribbon of ointment along the inside of the lower lid. Close eyes gently without squeezing the lids shut. Roll eyes to distribute the medication over them.
  5. Remove excess solution or ointment outside your eye with a clean tissue, using a separate tissue for each eye.
  6. Wash hands after you have finished your medication, to avoid transmitting the infection to others.
  7. If you are using an eye ointment you may experience blurred vision for approximately 20 minutes after application. This is expected and will resolve on it own.


Jacobs, D. (2006). Conjunctivitis. UpToDate Web site; search for conjunctivitis
American Academy of Family Physicians, – search “conjunctivitis” then link to