Contact lenses that are not properly cleaned and disinfected increase the risk of severe eye infection. Any lens that is removed from the eye needs to be cleaned and disinfected before it is reinserted. The storage case also needs to be cleaned, since it is a potential source of infection.
Researchers studied the rate of contamination in contact lens storage cases by taking samples of the contact lens disinfection solution from lens cases belonging to candidates for refractive surgery. In two-thirds of the storage cases, at least one pathogen was detected.
The most common pathogen was Pseudomonas, a known cause of severe corneal infections. Fungal pathogens were found in some cases.
Pathogens were found in all of the types of storage solutions that were studied; some solutions tested positive for pathogens every time they were tested. The pathogens can cause keratitis, an often painful inflammation of the cornea. Complications from keratitis can lead to vision loss.