Most counterfeit contact lenses are contaminated, says FDA

Almost two-thirds of counterfeit contact lenses tested positive for microbial contamination in a US study, raising the risk of serious eye damage among users.

Researchers from the FDA's Forensic Chemistry Centre in Ohio analysed 300 samples from 29 different brands of non-corrective lenses – typically used for cosmetic purposes – and found that nearly half (48 per cent) had at least one sample that contained microbes.

Overall, they found that 60 per cent of counterfeit lenses (37 of 62) tested in the lab were contaminated with bacteria, as were 29 per cent of unapproved lenses (61 of 233). Several of the bacteria species found in the lenses are linked to serious eye problems, including Bacillus cereus and Pseudomonas aeruginosa, which are known to cause corneal infections. Poorly-made contact lenses can also scratch the cornea, raising the risks of infection still further.

Decorative and coloured lenses are becoming increasingly popular but consumers who don't source them from reputable suppliers – with a prescription - are risking severe and potentially irreparable damage to their eyesight including blindness, say the researchers. They have published their findings in the Journal of Forensic Sciences.

These products are regulated as Class II or Class III medical devices in the US and should never be purchased from a street vendor, a beauty supply store, flea market, novelty store or tattoo parlours, says the FDA website, which continues: "it's very important that you only buy contact lenses from a company that sells FDA-cleared or approved contact lenses and requires you to provide a prescription."