The FDA sent warning letters to eight companies selling unapproved eye products that claim to treat pink eye, glaucoma, cataracts, and other eye issues. Marketing products like these without FDA approval is illegal and can put consumers at risk. CVS and Walgreens are removing the products from shelves, and customers can return purchased items for a full refund.

These products are particularly risky because the body is more vulnerable to substances applied directly to the eyes. Products that contain silver are especially concerning: they can cause the skin and other body tissues to permanently turn gray.

A full list of unapproved eye products is available on the FDA website. The agency encourages consumers who have been using these products to speak to their health care provider.

Companies have 15 days after receiving the FDA’s warning letters to respond. If companies don’t stop manufacturing and marketing unapproved products, the FDA may take legal action. CVS and Walgreens have already started taking these drugs off their shelves, and customers who have already purchased them can return them for a full refund.