Eye infections can invade the eyeball or the area around it – they are generally microorganisms that can be harmful, including viruses, bacteria and fungi.
Conjunctivitis is a common infection usually caused by bacteria or virus; it’s very contagious and often affects children in schools or other places where it is easily passed from child to child. It gives the eye a pink tinge, which is why it is also known as ‘pink eye’.
There are other types of infections caused by viruses (viral keratitis), such as ocular herpes caused by the herpes simplex virus.
Fungal eye infections (fungal keratitis) can be caused by a penetrating injury allowing the fungus to invade the area.
People who wear contact lenses are vulnerable to infections caused by parasites (acanthamoeba keratitis) which can be serious and even threaten sight. Contact lens users generally need to take special precautions and ensure lenses are well cared for and cleaned properly.
The trachoma infection is very common in some areas of the developing world where it may also be one of the main causes of blindness. It can be spread by flies and one of the main problems with this is reinfection and so proper hygiene and access to treatment is essential.
Endophthalmitis is a bacterial infection that affects the inside of the eye (because of an injury or very rarely after eye surgery) and can cause blindness without immediate powerful antibiotic treatment. There is also a type of mould that can cause the problem, although this is rare.
Mould that penetrates the eye’s interior also can cause endophthalmitis, though rarely.
A stye of chalazion is an infection that affects the inside of the eyelids.
Dacryocystitis is an infection of the tear ducts that inflames and blocks the system that drains tears from the eyes.
Corneal ulcers can be caused by an infection and may be connected to the use of contact lenses; these are serious infections and can result in very severe loss of vision if they are not treated.
There are some infections – such as endophthalmitis – that go deeper into the inside areas of the eye and they can be sight-threatening.
Orbital cellulitis may attack the soft tissue around the eyelids and this infection is a serious emergency and needs treatment to stop it spreading.
With early diagnosis and treatment, most of the common bacterial infections will resolve themselves with the use of prescribed medications such as antibiotics – eye drops, ointments and compresses.
Most viral infections disappear with little effort but if they are severe, antiviral drops may be needed to reduce inflammation.
Good hygiene and especially hand washing is essential before touching any area of the eye and when using contact lenses.