(NewsNation) — Scammers are trying to sell counterfeit solar eclipse glasses ahead of next Monday’s event.

During the solar eclipse, the moon will move across the sun, covering the light and making the sky look dark. Once the sun is covered completely, or under totality, it’s okay to look at the sky, but before and after the eclipse, you should wear eclipse glasses to avoid eye damage.

Experts warn staring at the sun during the solar eclipse without protective eye care can put you at risk for permanent eye damage.

When buying eclipse glasses, you’ll want to make sure you’re buying from a reputable vendor and know how to identify the key markers that prove the glasses are eclipse-proof. However, counterfeit eclipse glasses are “polluting the marketplace,” according to the American Astronomical Society (AAS).

“There’s a lot of people trying to capitalize on it. They’re flooding the market with low-price glasses, and that’s just scary to me,” American Paper Optics CEO John Jarret told NewsNation.

The fake glasses may be difficult to spot; experts recommend these steps to ensure your solar eclipse glasses are legit.

How to spot fake eclipse glasses

An authentic and safe pair of solar eclipse glasses should be labeled “ISO 12312-2” and have an authentic ISO certification label.

Your solar eclipse glasses should also state the following:

• Authentic solar filters
• Proper fit and full coverage
• Reputable manufacturer and vendor
• Free of any defects, punctures, and scratches
• No distortion and proper transmission of limited light

If you already bought glasses and want to ensure they are safe, the American Astronomical Society has a full list of suppliers of safe solar viewers and filters you can check here. 

Where to purchase approved solar eclipse glasses?

Here’s a list of approved American Astronomical Society sellers:

• American Paper Optics
• Rainbow Symphony
• American PaperWear 
• Halo Eclipse Spectacles
• Celestial Optical
• Thousand Oaks Optical
• Seymour Solar 
• DayStar Filters

Some large retailers including Wegmans, Walmart, Kroger and Buck-ee’s also sell eclipse glasses.

If you’re looking on Amazon, here’s a list of approved sellers.

Can I make my own solar eclipse viewer?

You can also make your own eclipse viewer from a cereal box if you want to save money, or use two sheets of paper to make a pinhole projector.

NewsNation affiliate WSYR contributed to this report.