Philip Walsh - What are the causes of conjunctivitis?

What causes conjunctivitis?
There are four main reasons why people get conjunctivitis, ranging from allergies, irritants, bacteria and viruses.

Bacterial conjunctivitis is caused by organisms such as staphylococci, streptococci or haemophilus. These bacteria may already be residing on the body's skin or in the upper respiratory tract. Sometimes, the bacteria can be caught from contact with another person who has conjunctivitis.

This type of conjunctivitis can be infectious, so you are at risk of getting it if you handle objects that have been contaminated such as cosmetics, false eyelashes, hands, washcloths, and goggles, if the person wearing or using them previously had an infectious type of conjunctivitis. People often rub or touch their eyes throughout the day, so if you have come into contact with a contaminated object and then transferred your hands to your eyes, this could increase your risk of getting the condition.

Viral conjunctivitis is highly infectious and can be spread even more easily than the bacterial form. It can be transferred from person to person through the touching of contaminated items as well as coughing or sneezing. It's also typically associated with viruses causing colds or sore throats.

Allergic conjunctivitis is caused by an allergy to an antigen in the person's environment. Often these will be fairly common substances such as pollen, dust mites and some types of cosmetics. If you have other allergies such as asthma, hay fever or eczema then you are also more likely to experience this form of the condition. This will usually go away once the underlying allergy has been treated.

Similarly, reactive conjunctivitis is caused by the eye's response to a chemical or other irritant. This could be anything from the chemicals in swimming pool water to smoke, fumes or other substances in the atmosphere.

For more information on conjunctivitis and treatments, visit www.specsavers.co.nz.