We are just under three weeks away from the highly anticipated total solar eclipse - and as we get closer, the supply of ISO certified eclipse glasses continues to dwindle.

Tuesday morning, Boise libraries were giving away 2,000 glasses, and in a matter of minutes all of them were gone.

Now that those are gone, many of you are wondering where you can get your hands on eclipse glasses that are safe. The scary part is that anyone can try and make a quick buck and sell glasses that look like they're the real deal when in reality they may not be.

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Brian Jackson, an assistant professor in the Physics Department at Boise State University, says having the right pair of eclipse glasses is vital.

Jackson says he's gotten questions like, "What makes these glasses different than regular sunglasses?" He says eclipse glasses have a special filter on them making them more powerful against the sun's UV rays.

"Safe eclipse shades should have an ISO marking on the back marked with ISO 12312-2," Jackson said. "That's the number they want to look for on the eclipse shades that tells them that it's safe to use to look at the sun. If you don't have that on your eclipse shades it's not clear that they're safe to use."

If you don't have eclipse glasses or the ones you have don't have that number on them, you could do some permanent damage to your eyes.

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Dr. Chad Cleverly at Boise Vision Care in Boise says many people plan on using a telescope or binoculars to watch, but unless you have special filters that go at the end of those lenses you could damage your eyes even more.

"Looking at the sun for any prolonged period of time can cause solar retinopathy, which is basically a photo chemical disruption of your retina, which basically is almost like a burn," said Dr. Cleverly. "You end up with a scar at the back of your retina, which is permanent - there's no treatment for it."

Dr. Cleverly says if you don't wear proper eyewear and watch the eclipse you will feel the symptoms immediately, symptoms like a spot of blurry vision or a blind spot right in the center of your vision.

A lot of places are running out of glasses as we get closer to the big day, but stores like Walmart are selling them - and KTVB will be distributing ISO-certified eclipse glasses at the Total Eclipse of the Fair to fair ticket holders.