Conjunctivitis is a common and uncomfortable eye condition that can be caused by infections, allergies or irritants.
The conjunctiva is thin clear tissue covering the front of the eye. One or both eyes may be affected, and the condition can spread from one to the other.
Causes of conjunctivitis include:
- Bacterial or viral infection
- Infection with a virus that may also cause a fever and sore throat
- Sexually transmitted infections (STIs), including chlamydia and gonorrhoea
- Irritants such as chlorine from swimming pools, shampoo, smoke, fumes or a loose eyelash
- Seasonal allergic conjunctivitis and perennial (all year round) allergic conjunctivitis, caused by pollen, dust mites or pet dander
- Contact dermatoconjunctivitis, from eye drops, chemicals or make-up
- Giant papillary conjunctivitis, from wearing contact lenses, eye surgery stitches or any tubes or things fitted during eye operations.
Who has a greater chance of getting conjunctivitis?
People who have a greater chance of getting conjunctivitis include:
- Those close to a person with conjunctivitis. Conjunctivitis from infections is very easily spread to other people around you, so precautions should be taken, such as not sharing towels and always carrying out good handwashing. Commuters on crowded trains also have a greater chance of picking up conjunctivitis.
- Older people. Older people's immune systems may be less able to fight the infections.
- Children. Children are more likely to be in close contact with other children with eye infections at school or playing.
- Those who've had a recent cold or upper respiratory tract infection.
- People with diabetes or conditions that can lessen the body's defences.
- Those taking steroids (corticosteroids).
- Having blepharitis infection causing inflammation of the rims of the eyelids.
Symptoms of conjunctivitis may be different depending on what's caused it, but often includes:
- Red eyes.
- Sticky discharge.
Conjunctivitis from an infection may also cause:
- A burning feeling in the eyes.
- A gritty feeling in the eyes.
- Eyelashes having a sticky coating first thing in the morning.
- Enlarged ear lymph node (lymph gland).
Conjunctivitis allergies may also cause:
- Eyes itching
- Watery or running eyes.
Conjunctivitis diagnosis and treatment
Seek medical advice if you have conjunctivitis symptoms - especially extra sensitivity to light, severe eye pain or blurred eyesight. Babies with conjunctivitis need urgent medical care.
It is important for a health professional to work out which kind of conjunctivitis it is so the right treatment can be given, when necessary, to clear up the discomfort and avoid possible complications.
In many cases, conjunctivitis caused by infections will clear up after a couple of weeks without treatment. However, some kinds of conjunctivitis are more serious or are a sign of another serious condition or eye problem such as glaucoma.
A sample of discharge from an eye may be taken with a swab for laboratory testing.