Emma Marsden, a 47-year-old from Lancashire, faces the potential permanent loss of sight in her right eye after a parasite burrowed into her cornea. The devastating infection, known as Acanthamoeba keratitis, was triggered by a seemingly minor mistake: washing her face with contact lenses still in after a fall.
Marsden's ordeal began in February when she fell into a wheelbarrow filled with dirt and water while cleaning horse stables. She cleaned her face afterward but did not remove her contact lenses until later that evening. Four days later, her right eye began to sting, with the pain rapidly intensifying and her vision deteriorating. Initially diagnosed with an ulcer and sent home with eye drops, the pain became unbearable, leading to a complete loss of vision in the affected eye.
"My eye was excruciatingly painful and red," Marsden recounted. "Any time light hit my eye the pain was so severe I couldn’t open my eyes."
During a follow-up appointment in March, doctors identified the culprit as Acanthamoeba keratitis, a rare infection caused by a microscopic organism that invades the cornea. This organism can consume the corneal tissue and nerves, a speed of progression that surprised medical professionals.
Doctors believe Marsden contracted the infection when she washed her face with her contacts still in, as Acanthamoeba is commonly found in tap water, as well as in lakes, oceans, rivers, swimming pools, hot tubs, soil, and dust. While the infection can affect anyone, it is most prevalent among contact lens wearers. The Cleveland Clinic estimates approximately 1,500 cases occur annually in the U.S.
"I’ve had three kids and giving birth is a dream compared to this pain," Marsden said, describing being confined to a dark room for three and a half weeks.
Doctors discovered the parasite had perforated her cornea, necessitating surgery to sew her eyelid shut in an effort to promote healing. Marsden has been informed that she will eventually require a corneal transplant, but the procedure must be postponed for several years due to the ongoing infection. She expressed that if her condition does not improve significantly, she would opt for eye removal.
Marsden is currently undergoing weekly monitoring at the hospital and must administer eye drops every two hours. She is now sharing her story to urge other contact lens users to adhere to strict hygiene practices.
"It was the wearer [me] not having the knowledge of how to look after them properly and what not to do," Marsden stated, emphasizing that the contact lenses themselves were not the sole cause of the infection.
In the United States, an estimated 45 million people wear contact lenses. When used correctly, experts say they are a safe vision correction method. However, improper handling and poor hygiene can lead to serious complications, including Acanthamoeba keratitis, corneal ulcers, and conjunctivitis. These infections often occur when harmful microbes enter the eye through inadequate cleaning, incorrect lens storage, the use of expired products, or exposure to water. Sleeping in contact lenses also significantly increases the risk, making wearers six to eight times more likely to develop an eye infection, according to the CDC.