Contact Lens Infection Nearly Blinds High-Schooler Ashley Hyde: How Dangerous Are They?

If you wear contact lenses and don't regularly change them or practice good contact lens hygiene, let this be a lesson for you.

Ashley Hyde, an 18-year-old from Florida, nearly went blind because of a parasite on her contact lens called Acanthamoeba, Local10 reported.

The parasite, which was eating through her cornea when doctors found it, caused blurry vision and inflammation, the New York Daily News reported. Hyde even had to have her eye scraped by doctors to gather cultures of the organism.

"One time, they had to drill into my eye. It was really nasty," Hyde told Local10.

Acanthamoebas are known to infect the eyes -- along with causing infections on the skin and in the brain -- and come from water and soil. This type of amoeba most commonly infects people via contact lenses, skin cuts or wounds, or via lung inhalation, the Centers for Disease Control and Prevention reported. The amoeba is known to cause three diseases: Acanthamoeba keratitis (eye infection that could lead to blindness), granulomatous amebic encephalitis (dangerous brain and spinal cord infection), and disseminated infection (widespread infection).

Keratitis, the medical term for cornea infection, isn't only caused by amoebae like Acanthamoeba -- it can also be caused by bacteria, fungus or even herpes, according to the American Academy of Ophthalmology. Big risk factors for getting an infection from contact lens use include sleeping in contact lenses, using "extended-wear" lenses that are designed so that you don't often change them, or having poor contact-lens hygiene (like reusing solution), and having a reduction in tears beneath the contact lenses.

In 2007, there was an outbreak of Acanthamoeba keratitis in the United States, that led to the recall of Advanced Medical Optics Complete MoisturePlus contact solution (though a 2009 article in the journal Emerging Infectious Diseases showed that the association was likely not from contamination during the manufacturing process). To this day, the Centers for Disease Control and Prevention report that levels of infection of Acanthamoeba keratitis have still not decreased to that of pre-2007.

But still, the infection is considered relatively rare, the CDC reported. The CDC noted that there is no specific information on the number of infections from Acanthamoeba keratitis because reporting of cases is not required.

Earlier this year, the Telegraph reported on a 42-year-old woman who had her eye removed because of an infection. The woman, Jacqueline Stone, has filed a lawsuit because she says her Focus Dailies All-Day Comfort contact lenses caused the infection.