As customers prepare for next week’s total solar eclipse, Amazon has issued a recall for some of the eclipse glasses sold on its internet marketplace, saying it was unable to confirm whether the protective ware was made by a recommended manufacturer.

NASA and the American Astronomical Society have been urging solar gazers to use glasses engineered by reputable vendors that carry the international safety standard number “ISO 12312-2.”

Eclipse glasses made under these standards block 100,000 times more light than ordinary sunglasses. Even brief, unprotected glimpses of the sun can cause blurry vision or blindness. The American Astronomical Society has spotted counterfeit eclipse glasses on Amazon in the past.

The company has not released the scale of the recall or a public list of offending vendors…

Amazon began emailing customers about the safety recall on Saturday. The internet retailer decided to double-check the suppliers “out of an abundance of caution,” an Amazon spokesperson wrote in a statement to NewsHour. The company has not released the scale of the recall or a public list of offending vendors, but says it has offered refunds to customers who purchased the affected glasses.

“Viewing the sun or an eclipse using any other glasses or filters could result in loss of vision or permanent blindness,” Amazon wrote in its email to impacted customers. “Amazon has not received confirmation from the supplier of your order that they sourced the item from a recommended manufacturer. We recommend that you DO NOT use this product to view the sun or the eclipse.”

Yet the company’s spokesperson told NewsHour they weren’t listing specific brands or products “because there may be legitimate versions under the same name.”

Customers with concerns should keep a close watch on their inboxes, as Amazon only sent emails to people who bought unvalidated glasses. Those who did not receive an email should be safe and clear to use their glasses, the company said.

But Amazon’s sudden decision pull these eclipse glasses has left some suppliers in the dark. Manish Panjwani, who runs the astronomy product supplier AgenaAstro, told KGW that Amazon pulled his eclipse glasses even though he provided documentation confirming the authenticity of their manufacturers. Panjwani worries his customers may now look elsewhere and potentially fall prey to scams.

“People have some of the best glasses in the world in their hands right now and they don’t believe in that product,” he told KGW. “They’re out there looking for something inferior.”