In just two weeks, people around the U.S. will be looking to the sun to watch the solar eclipse.

However, many may be unknowingly looking through counterfeit lenses that won't protect their eyes.

If you're gearing up with protective eyewear, experts want you to be aware of possible fake lenses being sold on the internet.

The American Astronomical Society says it's seeing an alarming number of glasses being sold online that don't come from the dealers they've tested and verified as safe.

At, pages of eyewear for viewing the eclipse are being sold. Most of them claim to be certified safe, but American Astronomical Society press officer Dr. Rick Fienberg says that unless the eyewear is sold by approved vendors, there's no way to know for sure.

"It's not that hard to make a dark film that reduces the sun's visible brightness to a comfortable level. The challenge is making sure that you know that it's also blocking the sun's invisible light," Fienberg said.

"I've looked through a number of fakes that actually produce pretty decent images of the sun, and for all I know, they're safe. But I don't know for sure. And if I only have two eyes, I'm not going to be able to replace them, so I don't want to take that risk.

Fienberg says that originally, the American Astronomical Society was advising people to look for an "ISO 12312-2" certification printed on eclipse viewing glasses. But because many unverified vendors are now printing this on their glasses, the society issued an approved list of vendors.

You may have also heard about 2 million pairs of glasses being given out by libraries around the country. Those glasses from that program are from a reputable vendor.