Eye infection

An eye infection occurs when micro-organisms such as bacteria, viruses, fungi or parasites enter the eye or the surrounding tissues and cause an inflammatory reaction. It can affect different parts of the eye, each with its own characteristics and severity.

Types of eye infections

Depending on the location and the causative agent, there are various forms:

• Conjunctivitis: an inflammation of the conjunctiva, the mucous membrane lining the inside of the eyelids and the white of the eye. This can be bacterial, viral or allergic in nature.
• Keratitis (corneal inflammation): an infection of the cornea, often more serious and carrying a risk of scarring and vision problems. It is more common amongst contact lens wearers who use their lenses incorrectly or do not maintain adequate hygiene.
• Blepharitis (eyelid inflammation): an inflammation of the eyelid margins, often chronic and caused by bacteria or skin conditions.
• Hordeolum (stye): an acute bacterial infection of a gland in the eyelid.
• Endophthalmitis: a serious infection inside the eye, usually following eye surgery or penetrating trauma.

Causes and risk factors

Eye infections can be caused by direct contact with contaminated hands, towels or make-up, by wearing contact lenses without proper hygiene, by injuries or by spreading from other parts of the body. Contact lens wearers are at increased risk, particularly when sleeping in their lenses, using contaminated lens solution or failing to replace the lens solution.

Recognition

Possible symptoms include redness, pain, itching, a burning sensation, discharge (white, yellow or green), increased tear production, sensitivity to light, swelling of the eyelids, a sensation of a foreign body in the eye, or blurred vision. The severity and combination of symptoms vary depending on the type of infection.

When to see an ophthalmologist or optician

If you suspect you have an eye infection, always have it assessed by your optician, optometrist or ophthalmologist. Some infections are mild and clear up on their own, but others can be serious and require prompt treatment to prevent permanent damage. Professional assessment is particularly necessary in cases of pain, impaired vision, severe redness or discharge.

Contact lenses and eye infections

If you wear contact lenses and experience symptoms that suggest an infection, remove the lenses immediately and do not wear them again until your eyes have been examined. Many eye infections in contact lens wearers are caused by poor hygiene, the use of contaminated or expired lens solution, sleeping in lenses not designed for that purpose, or wearing disposable lenses for too long. Always follow the instructions for use for your lenses and solution, wash your hands before putting them in or taking them out, and replace your lens solution daily.

Reducing the risk of infection

Good hand hygiene is the most important precaution: wash your hands regularly and avoid touching your eyes unnecessarily. Do not share towels, pillows or eye make-up with others. Replace eye make-up regularly and do not use it whilst you have an active infection. For contact lens wearers: stick to your wearing schedules, use only fresh lens solution, and replace your lens case as recommended.

Treatment

Treatment depends on the type and severity of the infection and is determined by an ophthalmologist. Bacterial infections may require antibiotic eye drops or ointment; viral infections are often treated symptomatically; and fungal or parasitic infections require specific medication. Never use leftover eye drops or medication from other people; this can make the situation worse.