The Food and Drug Administration is warning the public against copycat eye drops because of the risk of infection.

South Moon, Rebright and FivFivGo eye drops are offered in packaging that could easily be mistaken for Bausch + Lomb's Limify brand eye drops, an over-the-counter product approved for redness relief, the FDA said on Wednesday.

The copycat products claim to address conditions like glaucoma, which is treated with prescription drugs or surgery, the agency noted. 

The FDA tested samples of South Moon and Rebright eye drops purchased online, finding the former to be tainted with burkholderia cepacia complex, a group of bacteria that could cause an antibiotic-resistant infection. While Rebright testing did not find contamination, the agency advised against its use.

FDA testing also found South Moon and Rebright drops lacked brimonidine tartrate, the active ingredient in Limify. The agency was not able to obtain FivFivGo samples. 

The origin of the copycat products is not yet clear, but the federal agency continues to investigate. 

The FDA has received reports related to possibly fake Lumify including quality concerns, eye irritation, pain and infection, according to the agency, which advised eye drop users to only buy products from reputable retailers, like state-licensed pharmacies. 

The warning comes just months after an eye drop recall in which 28 products were pulled from store shelves due to safety concerns prompted by investigators finding unsanitary conditions at a manufacturing facility in India. That November recall was one of eight separate announcement related to eye drops last year. 

The spate of recalls involving eye drop products last year were linked to four deaths and multiple cases of vision loss.

More from CBS News

Kate Gibson is a reporter for CBS MoneyWatch in New York.