Conjunctivitis is an inflammation of the conjunctiva. The conjunctiva is the thin clear tissue that lies over the white part of the eye and lines the inside of the eyelid.
What causes conjunctivitis?
Conjunctivitis has a number of different causes including:
- Bacteria (such as gonorrhoea or chlamydia)
- Irritants such as shampoos, dirt, smoke and swimming-pool chlorine
- Allergies such as dust and pollen, or a special type of allergy that affects some contact lens wearers
Conjunctivitis caused by some bacteria and viruses can spread easily from person to person, but it is not a serious health risk if diagnosed promptly.
What are the symptoms of conjunctivitis?
The symptoms of conjunctivitis differ depending on the cause of the inflammation, but can include:
- Redness in the white of the eye or inner eyelid
- Increased amount of tears
- Thick yellow discharge that crusts over the eyelashes, especially after sleep
- Green or white discharge from the eye
- Itchy eyes
- Burning eyes
- Blurred vision
- Increased sensitivity to light
Seek medical advice if you have any of these symptoms of conjunctivitis. You may be advised to attend for an examination of your eyes and a sample of fluid from the eyelid using a cotton swab may be taken to be analysed in a laboratory. Bacteria or viruses that may have caused conjunctivitis, including a sexually transmitted infection (STI), can then be identified and appropriate treatment prescribed.
How is conjunctivitis treated?
The treatment for conjunctivitis depends on the cause:
- Bacteria. Conjunctivitis caused by bacteria including STIs is treated with antibiotics in the form of eye drops, ointments or pills. Eye drops and ointments may need to be applied to the inside of the eyelid several times a day. Pills may need to be taken for several days. The conjunctivitis should improve within a week. Take the medicine as instructed by your doctor, even if the symptoms of conjunctivitis go away.
- Viruses. This type of conjunctivitis often results from the viruses that cause a common cold. Just as a cold must run its course, so must this form of conjunctivitis, which usually lasts from four to seven days.
- Irritants. For conjunctivitis caused by an irritating substance use water to wash the substance from the eye for five minutes. Your eyes should begin to improve within four hours after washing away the substance. If the conjunctivitis is caused by an acid or alkaline material such as bleach, seek urgent medical advice.
- Allergies. Allergy-associated conjunctivitis should improve once the allergy is treated and the allergen removed. Seek medical advice if you have conjunctivitis that is linked to an allergy.
Traditionally, home remedies are sufficient for soothing conjunctivitis associated with uncomplicated colds, minor infections, or allergies. Treatment consists primarily of cleansing the eyes and preventing the condition from spreading.