Bacterial eye infection

What causes bacterial eye infections?

The causes of bacterial eye infection may vary, but they may be triggered by:

• bacteria, such as the strains that are often found in ear and lung infections
• bacteria which cause sexually transmitted infections (STIs), like gonorrhoea or chlamydia

Eye infections can be caused by different bacteria, sometimes causing different symptoms. For instance, conjunctivitis caused by the Morax-Axenfeld diplobacilli bacteria often lasts much longer than other forms of bacterial conjunctivitis and may require further treatment. However, bacterial eye infections are most commonly caused by bacteria similar to that which causes respiratory infections.

By extension, there are several types of conjunctivitis, such as allergic conjunctivitis’ which can be caused by:

• pollen
• dust mites
• contact lenses
• chlorinated water
  found in swimming pools
• certain shampoos
• fumes or smoke
• stray eyelashes which rub against the conjunctiva (tissue that covers the white area of the eye and the inside of the eyelids)

What are the symptoms of bacterial eye infections?

Symptoms of an eye infection will differ depending on the cause of infection. However, common symptoms of bacterial eye infections include redness and swelling, caused by the inflammation of the blood vessels in the thin layer of cells that cover the eyes, and unusual discharge. There is also sometimes a gritty or scratchy feeling. Symptoms tend to be experienced in just one eye to begin with, but usually affect both eyes within several hours.

Can bacterial eye infections lead to other problems?

Some bacterial eye infections can have serious complications if not treated. Conjunctivitis, for example, can lead to complications, depending on whether it’s infective or allergic conjunctivitis. There's special concern around bacterial conjunctivitis that's caused by sexually transmitted diseases, such as chlamydia and gonorrhea, which can threaten vision. Infective conjunctivitis, if left untreated, can lead to meningitis, or blood poisoning (septicemia), among other things. Another complication known as bacterial keratitis (bacterial infection of the cornea) can cause blindness if left untreated. If there are changes in your vision, you should get in touch with a clinician immediately.