There are five different kinds of , each with its own cause. Bacterial is an infection caused by bacteria such as staphylococci, streptococci or haemophilus. These organisms may come from the patient's own skin or upper respiratory tract or they may be caught from another person with conjunctivitis. Viral is often associated with the common cold. This may be caused by a virus called 'adenovirus'. This type of conjunctivitis can spread rapidly between people and may cause an epidemic of conjunctivitis. s This type of is caused by an organism called Chlamydia trachomatis. This organism may also affect other parts of the body and can cause the venereal disease chlamydia. s Allergic is common in people who have other signs of allergic disease such as hay fever, asthma and eczema. The conjunctivitis is often caused by antigens like pollen, dust mites or cosmetics. Reactive - chemical or irritant conjunctivitis Some people are very susceptible to chemicals in swimming pools or to smoke or fumes and this can cause an irritation of the conjunctiva with discomfort, redness and watering. In such cases these irritants should be avoided. | 
