Conjunctivitis (Pink Eye)

Conjunctivitis (Pink Eye)

What is conjunctivitis?

More commonly known as 'pink eye' and sometimes as 'red eye'1, conjunctivitis is characterised as an inflammation (or infection) of the conjunctiva (the thin, transparent membrane that lines the inner surface of the eyelid, covering the white of the eyeball, known as the sclera). Tiny blood vessels (capillaries) in the conjunctiva become irritated or inflamed which causes them to dilate (swell up), making them more visible in the eye, and resulting in the reddish-pink discolouration which occurs.

Conjunctivitis is generally more unpleasant to look at than it is harmful to a person’s visual capability. The numerous types of pink eye relate to their various underlying causes, the most common of which are viral1 and bacterial infections, however allergies, chemical agents and irritants may also trigger the condition. 

Both viral and bacterial conjunctivitis are highly contagious, so it is important for a medical doctor to thoroughly evaluate a case of pink eye in order to determine the underlying cause, and if necessary, possibly prevent further transmission (i.e. spreading to another person). Interestingly, most doctors will only refer to the condition as ‘pink eye’ when it has a viral cause.

Conjunctivitis is a fairly common eye condition, especially in children (often due to viral causes). One or both eyes can be affected (i.e. inflammation due to infection may affect one eye at first and then spread to the other) and for most is little more than a mild eye infection. In rare instances, conjunctivitis can lead to more serious medical complications involving the eye.

Illustration depicting the structure of the eye.



1. American Academy of Opthalmology. August 2017. Treatment of Acute Conjunctivitis in the United States and Evidence of Antibiotic Overuse: Isolated Issue or a Systematic Problem?: [Accessed 20.08.2018]

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