Pediatric Ophthalmology Consultants

What is Conjunctivitis?

Conjunctivitis is the term used by medical eye doctors to describe inflammation of the conjunctiva. In ordinary terms, conjunctivitis is simply the most common cause of “pink eye”.

The white of the eye (the sclera) is covered by a thin, filmy membrane called the conjunctiva which produces mucous to coat and lubricate the surface of the eye. It normally has fine blood vessels within it, which can be seen on close inspection. When the conjunctiva becomes irritated or inflamed, the blood vessels which supply it enlarge and become more prominent, and the eye looks red.

What causes conjunctivitis?

Many different sources of eye irritation can cause conjunctivitis. The most common are infections, allergies and environmental irritants. Because the conjunctiva is a simple tissue, it responds to all these stimuli in one way; it turns red. Infectious causes of conjunctivitis include bacteria and viruses. Bacterial infections cause a red eye which is associated with considerable amounts of pus. If the amount of the discharge from the eye is great, an infection is likely, and prompt consultation with an ophthalmologist is advisable. On the other hand, some bacterial infections may produce little or no discharge except for some mild crusting of the eyelashes in the morning.

Viruses are also common causes of conjunctivitis. Some viruses produce the familiar red eyes, sore throat and runny nose of a common cold. Other may infect only one eye. Viral conjunctivitis usually produces a watery discharge and lasts from one to two weeks.

Infectious conjunctivitis whether bacterial or viral, can be quite contagious, so contact with the patient’s tears through handkerchiefs and towels should be avoided. Hand washing after contact with the patient helps prevent spread of infection.

Other causes of red eyes

There are several eye diseases which also produce a red eye and which can lead to blindness unless recognized and treated. It is important to avoid confusing them with conjunctivitis, so a medical evaluation of a red eye by an ophthalmologist is always a good idea. This is especially important if pain, blurred vision or severe light sensitivity are present, since the symptoms are not usually found in simple conjunctivitis

American Academy of Ophthalmology

The Eye M.D Association


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