There are horrible things lurking on counterfeit contact lenses
Bacterial endophthalmitis sets in quickly, causing pain, redness, and vision loss. This inflammation inside the eye "often culminates with surgical removal of the eyeball or the contents of the eye." The bacterium Bacillus cereus is one of the common causes of bacterial endophthalmitis, and it is just one of several nasty microbes recently detected on counterfeit contact lenses.
There's a law that says people can only get contact lenses through a doctor's prescription—even if they're just for decorative purposes, like cosplay or Halloween—and that the FDA has to approve a contact lens brand before it can be sold in U.S. markets. But in this day and age, it's not hard to work around the law.
In a new study, researchers at the FDA's Forensic Chemistry Center in Ohio tested nearly 350 decorative, non-corrective contact lenses to see what was living on them, and the results, published in the Journal of Forensic Sciences, are somewhat disturbing.
Obtained without a prescription, 285 of the lenses came from novelty stores, tattoo parlors, import seizures, and of course, the internet. These lenses were suspected to be counterfeit and unapproved. The rest came from approved manufacturers.
To look for the bacteria, the researchers dropped each contact and some of its immersion fluid into a test tube full of broth, and incubated each one at 77 degrees Fahrenheit. After two weeks, they checked to see which tubes were cloudy—those were the ones growing clumps of bacteria. Then they'd take out those bacterial clumps and plate them onto petri dishes so they could grow. Then they scraped off a bacterial colony from each plate and tested its DNA to see what species it was.
They found that 60 percent (37 of 62) of the suspected counterfeit lenses, and 27 percent (61 of 233) of the unapproved lenses tested positive for microbial contamination. By comparison, only 3.7 percent (2 of 54) of the authentic, approved contact lenses were contaminated, and the study authors suspect this number is actually unusually high due to the small sample size.
That was for the individual lenses tested. The counterfeit lenses came from 29 different brands, 14 of which had at least one of their contacts test positive for bacteria. That's 48 percent.
Several of the bacteria species found in the lenses are associated with serious eye problems. They include B. cereus (mentioned above) and Pseudomonas aeruginosa, a common cause of microbial keratitis. If it's left untreated, this painful infection of the cornea can cause permanent vision loss or blindness.
Making matters worse, poorly fitted and poorly made contact lenses can scratch you, which helps bacteria infiltrate your eyeball.
"[A]cquiring contact lenses without a prescription is a considerable threat to consumer health and safety," the paper concludes.
So please, stop buying those over-the-counter lenses and go see your doctor instead. Yes, it's expensive and less convenient. But it's not as expensive as losing an eye.