Overview
The conjunctiva is the thin, clear membrane that covers the white of the eye and lines the inside of the eyelids. When it is inflamed, the small blood vessels in it show up and the eye looks red or pink.
Most conjunctivitis is caused by the viruses that cause colds, some by bacteria, and some by allergy or an irritant such as dust, smoke or chlorine. It usually gets better over a week or two without treatment.
Symptoms
- Redness or a pink colour in the white of the eye
- A gritty feeling, as if something is in the eye
- Itching, burning or soreness
- Watering, or a discharge of pus or mucus
- Lids stuck together, especially after sleep
One eye is often affected first and the other follows. Sight is usually normal, though discharge can blur it until it is wiped away. Allergic conjunctivitis itches a great deal, affects both eyes and comes with sneezing or a blocked nose.
When to see a doctor
See a doctor within a few days if you wear contact lenses, if the immune system is weak, if symptoms have not started to improve after about a week, or if bacterial conjunctivitis is no better a day after antibiotic drops were started.
Causes
- Viruses, including those that cause colds and flu
- Bacteria
- Allergens such as pollen, dust mites and animal dander
- Irritants such as smoke, dust, chlorine or shampoo
- Contact lenses, lens solutions, eye drops and eye ointments
- Some infections passed on during sex, which can also affect a newborn baby
Risk factors
- Close contact with someone who has infective conjunctivitis
- Sharing towels, pillows, washcloths or eye make-up
- Wearing contact lenses, especially if the case and solutions are not kept clean
- Hay fever, asthma or eczema, for the allergic kind
- A weakened immune system
Complications
Most conjunctivitis causes no lasting harm. Problems arise when the redness is not conjunctivitis but an infection or inflammation deeper in the eye, which can threaten sight.
Conjunctivitis in a newborn can be serious and needs to be seen straight away. In contact lens wearers, a red eye can mean an ulcer on the cornea.
Prevention
- Washing hands well with soap and water, especially after touching the eyes
- Keeping your own towel, washcloth and pillowcase, and washing them often in hot water
- Not sharing eye make-up, brushes, eye drops, spectacles or contact lenses
- Throwing away disposable lenses and cases used while the eye was infected
Diagnosis
Conjunctivitis is usually recognised from the story and a look at the eye: how it started, whether one eye or both are involved, what the discharge is like, and whether there is itching, pain or a change in vision.
The eye may be examined with a magnifying light, and a drop of dye can show scratches or ulcers on the surface. A swab is taken only in certain cases, such as a newborn baby or an infection that is not settling.
Treatment
Viral conjunctivitis is not helped by and clears in its own time. Comfort measures do the work: wiping the lids with cooled boiled water using fresh cotton wool for each eye, cold compresses, and lubricating drops from a pharmacy.
Antibiotic drops or ointment are used when a doctor judges the cause to be bacterial. Allergic conjunctivitis is treated by avoiding the trigger where possible and with anti allergy eye drops. Conjunctivitis in a newborn is treated urgently by a doctor rather than at home.
Myths and facts
Things people often say about this. Open each one to see what is true.
Myth“If you look into the eyes of someone with eye flu, you will catch it.”What is true?
Fact
Conjunctivitis does not travel through a glance. The infective kinds spread by contact: unwashed hands, rubbing the eyes, and sharing towels, pillows, washcloths, eye make-up or contact lenses. Sitting and talking with someone who has it does not pass it on.
Myth“Breast milk, kajal or a home-made drop will cure it.”What is true?
Fact
None of these is a treatment for conjunctivitis. What health services describe is simple: wiping the lids clean with cooled boiled water using fresh cotton wool for each eye, cold compresses, lubricating drops from a pharmacy, and antibiotic drops only when a doctor judges them necessary. Putting anything else into an inflamed eye is not treatment and can delay care for a problem that needs a doctor.
Myth“Every red, watery eye needs antibiotic drops.”What is true?
Fact
Most conjunctivitis is caused by viruses, and antibiotics do not work against viruses. Even bacterial conjunctivitis often improves on its own within a few days, so a doctor decides whether drops are likely to help.
Myth“Wearing dark glasses stops it spreading to others.”What is true?
Fact
Dark glasses can make bright light easier to bear, but they do nothing to stop the infection passing on, because it travels on hands and shared belongings. Washing hands often, not rubbing the eyes, and keeping towels, pillowcases and eye make-up separate are what make the difference.
Questions to ask your doctor
Tick the ones you want answered and take them with you.
Common questions
How long does conjunctivitis last, and how long am I infectious?
Most cases improve over a week or two without treatment. Infective conjunctivitis can be passed on for as long as the eye is red and watering or discharging, so careful handwashing matters throughout. See a doctor if there is no improvement after about a week.
Should my child stay home from school?
A child who feels well does not usually need to stay at home for conjunctivitis alone, though the school may have its own rule. What does matter is handwashing, a separate towel, and not rubbing or touching the eyes. A child who feels unwell, or who has eye pain or a change in vision, should be seen by a doctor.
Can I wear my contact lenses?
Leave them out while the eye is inflamed and wear spectacles instead. Throw away disposable lenses and the case that were used while the eye was infected, and only go back to lenses when symptoms have gone and an eye professional agrees.
How do I tell allergic conjunctivitis from an infection?
Allergic conjunctivitis usually affects both eyes, itches intensely, produces watery rather than thick discharge, and comes with sneezing or a blocked nose at a particular time of year or around dust or animals. It is not catching. If you are not sure, a doctor or pharmacist can help.
