It's up to a large retailer such as Amazon to make sure the company is not selling products that may be harmful to customers. Until US legislation strengthens or expands the FDA’s power, Amazon must keep these unapproved products off its retail platform. As currently constituted, the FDA is not empowered to track every new over-the-counter eye product that hits the market.
In fact, the FDA could do more to alert the public about these products before they cause harm. Even physicians aren't sure what to recommend to patients because 1% of eye drops can be problematic. Even under current guidelines, the FDA has enough power to monitor these products and inform everyone about them.
There's a 50% chance that Amazon will deliver some products by drone by March 2026, according to the Metaculus prediction community.