A corneal ulcer is an infection in the front window of the eye. It is an emergency level problem due to its ability to decrease vision or ultimately blind the eye that is infected. Those who sleep in their contact lenses are anywhere from 20 to 50 times more likely to get a corneal ulcer than non-wearers. Other risk factors are eye trauma, immune system compromised individuals, and those who battle severe levels of eye surface diseases.
Most corneal ulcers are caused by bacteria but other invaders that are seen can be viruses, fungi, and amoebas. Both viral and bacterial ulcers are very treatable due to the availability of effective medications. Once identified, a course of proper treatment often leads to a fast resolution minimizing scarring that can decrease vision.
Fungi and amoebas are considered exotic invaders and are difficult, if not impossible to treat in some cases. Those at risk have had trauma involving plant matter or contact lens abusers who are storing contacts in an unsanitary way. These infections do not respond to typical treatment and it is inevitably up to specialists to diagnose and treat them. They require specialized diagnostics that are available in a few locations and they require medications that are often toxic to the eye themselves.
To make matters worse, even when treated well they will often return because small spores are left behind that can become activated later on. It is important to get a red, blurry, and painful eye checked by an eye doctor, especially if you are a contact lens wearer, to ensure proper treatment.