If you’re planning to watch the solar eclipse this month, make sure you have the proper safety equipment.

Counterfeit eclipse glasses are flooding the market, according to the American Astronomical Society.

This isn’t much of a surprise, considering the excitement surrounding the Aug. 21 “Great American Eclipse,” when the moon will completely block out the sun in 14 states across the country.

It will be the first total solar eclipse that has been visible in the continental U.S. in more than three decades.

As for Arizona, only a partial eclipse will be visible, so it won’t be safe to look at without eye protection at any time.

ECLIPSE FACTS: How fast is the solar eclipse? And 32 other questions, answered

The Federal Trade Commission said only products marked with ISO 12312-2 have met the international safety standard and are safe for your eyes, but the American Astronomical Society said many counterfeit eclipse glasses are being labeled as if they’re ISO-compliant when they are not.

So how do you know your eyes are really being protected? Unfortunately, checking whether a solar filter meets the ISO standard requires specialized laboratory equipment.

The American Astronomical Society Task Force has been working put together a list of well known solar-filter brands that meet the safety standard. You can see the full list here.

If you already have a viewer from that list, make sure it isn’t more than three years old and does not have wrinkles or scratches.

You should also avoid dark sunglasses, neutral density or polarizing filters made for camera lenses, smoke glass, exposed film, “space blankets,” potato chip bags, DVDs and any other materials you may have heard about for viewing solar eclipses.

RELATED: 'Eclipse blindness' is a real thing. Here's how to watch the solar eclipse safely

If, somehow, you miss the big eclipse, you’ve got seven years to prepare for the next one. The next total solar eclipse in the U.S. will be on April 8, 2024 and will be visible from Texas to New England.