By Jamie Gumbrecht, CNN

CNN —
The FDA sent warnings letters to eight companies for marketing and manufacturing of unapproved eye products.
Sarah Silbiger/Getty Images

The US Food and Drug Administration on Monday sent warning letters to CVS, Walgreens and other companies over manufacturing and marketing of unapproved eye products the agency says could pose a risk to people who use them.
The agency said the products are illegally marketed to treat conditions including conjunctivitis — pink eye — glaucoma and cataracts, and some of the warnings cited sterility issues with the products.
The agency issued warning letters to CVS Health, Walgreens Boots Alliance Inc., Boiron Inc., DR Vitamin Solutions, Natural Ophthalmics Inc., OcluMed LLC, Similasan AG/Similasan USA and TRP Company Inc. Some companies have also been placed on import alert to stop products from entering the United States.
“The FDA is particularly concerned that these illegally marketed, unapproved ophthalmic drug products pose a heightened risk of harm to users because drugs applied to the eyes bypass some of the body’s natural defenses,” it said. Some of the products contain silver, which can cause areas of the skin or eye to permanently turn gray or blue-gray. People also might delay or stop safe and effective medical treatments while using these unapproved drugs, the agency said.
People using the products included the warning letters should speak to a health care provider, the agency said, and adverse events can be reported to the agency’s MedWatch program.
“We will continue to investigate potentially harmful eye products and work to ensure violative products stay off store shelves so that consumers can continue taking the medicines they need without concern,” Jill Furman, director of the Office of Compliance for the FDA’s Center for Drug Evaluation and Research, said in a statement.
The companies will have 15 days to respond to the letters to say how they’ll correct violations. Failure to make corrections could lead to legal action, the FDA said.

CNN reached out to the companies that received warning letters for a response.
In an email to CNN, CVS said it had stopped the sale of CVS Health Brand Pink Eye Relief Eye Drops in stores and online.
“Customers who purchased this product can return it to CVS Pharmacy for a full refund,” CVS said. “We’re committed to ensuring the products we offer are safe, work as intended and satisfy customers.”
Walgreens said it was pulling the products off shelves “out of an abundance of caution.”
“Customers who have purchased these products can return the item to their nearest Walgreens for a full refund,” it said.
TRP said there haven’t been any reports of health concerns or adverse events linked with its ophthalmic products and said “homeopathic drug products are not illegally marketed.”
“TRP will continue to work with FDA to ensure consumer access to products of their choosing. We will timely respond to the FDA’s warning letter,” it said in an email to CNN.
Boiron USA said it’s formulating a response to the FDA.
Similasan said it’s analyzing the situation and reaching out to partners.