Considering that demand, the American Astronomical Society has updated its safety advice "in response to alarming reports" of unsafe eclipse-viewers popping up online.
In news that surprises no one, demand for eclipse glasses has spiked, given the attention of the upcoming Great American Eclipse set for August 21, which will run across the continental United States. Take note, though - eclipse glasses aren't just sunglasses.
The Oak Ridge Public Library will give out 500 pairs of eclipse glasses to library patrons on Monday, August 14.
"It now appears that some companies are printing the ISO logo and certification label on fake eclipse glasses and handheld solar viewers made with materials that do not block enough [light]", AAS said.
"It's so risky for people to look at the sun even for brief periods of time because you can cause permanent damage to the retina - we call it solar retinopathy and it's really very close to burning a hole in the retina".
He encouraged families to protect themselves to properly enjoy the eclipse. Reuters reported that the market is being flooded with defective knockoffs, so it's also a good idea to make sure that the brand you purchased is approved by the experts before August 21.
Be sure to protect your eyes during the solar eclipse
"Some of the sun's radiation cannot be seen at all so someone looking at the eclipse without aid could be injured before they realize it", Schmude said.
"It's very important to wear these glasses because your eyes are precious, your vision is precious", he said.
Eclipses happen as the moon moves between the Earth and sun, casting a shadow across whichever part of the world that spins by.
One source told Business Insider that she had nearly purchased a five-pack of eclipse glasses on Amazon, before double checking the date - and realizing that they wouldn't arrive until September.
The business said the recall only applies to the Vision Source eclipse glasses sold last week.