A product meant to preserve heat is costing people their sight.

Thermos recalled over 8 million of its Stainless King Food Jars and Bottles after receiving 27 reports of customers being struck by a stopper that ejected from the product, leaving three with “permanent vision loss,” according to the Consumer Product Safety Commission.

The recall, announced April 30, covers three models: the Stainless King Food Jar, 40-ounce Sportsman Food & Beverage Bottle, and 24-ounce Stainless King Food Jar. The items were widely sold at major retailers, including Target, Walmart and Amazon, as well as on the company’s website, over several years.

According to the company, the issue stems from stoppers without a pressure-release mechanism. When perishable food or beverages are stored for extended periods, gas can build up inside the sealed container. Without a way to safely release that pressure, the stopper can eject with force when opened—posing a serious impact and laceration risk.

Basically, it’s what happens when a design flaw responds to a natural process. When any food ferments, it builds gas and pressure, and in this case, it caused the lid to be forced open.

But the risk isn’t limited to obviously spoiled food; even perishables that appear normal can begin to ferment if left unrefrigerated too long, especially in airtight environments. Think of a champagne cork popping off. That makes the defect less about extreme misuse but more about an effective missing safeguard in the product.

The company advised customers to immediately stop using the defective product and contact Thermos to receive a free replacement pressure relief stopper or a replacement, depending on the model. The company also asked customers to keep their recalled stopper until their claim has been approved, and, depending on availability, shipment of a replacement may take seven to nine weeks from the date all information was verified and processed by Thermos.

Online, reactions to the recall exploded with people calling out users who were clearly misusing the product.

“Even the recall note says clearly that this happens when food is left for an extended period of time. That’s not what thermos is designed for. I don’t get why companies do these recalls when people use the product wrong, lol,” said one Reddit user.

“Natural selection is really just playing the long game with our leftovers at this point,” another user wrote.

Some went as far as to even say that overall intelligence should be questioned.

“People stored food until it decomposed and built up gas and then took the lid off while looking directly at it. Poses no risk if your iq is above room temp,” one X user wrote.