Everyone is buzzing about the upcoming Aug. 21 solar eclipse. Even if you are not in the direct line of the eclipse, you might still want to head outside to see a partial eclipse.
As a result, demand is soaring for safe glasses for viewing it.
NASA caution about unapproved eyewear
But before you grab the first pair of "eclipse glasses" you find online, eye professionals are warning you to be careful of unapproved, or even discount/counterfeit glasses that might not provide any protection at all.
Shoppers we spoke with were a bit confused. Mom Dawn Garrison, concerned about her children's eyesight, is hearing conflicting advice about what to do.
"I understand we shouldn't look directly into the sun," she said. "So perhaps dark sunglasses maybe might be a good idea."
But skip the sunglasses, optometrists and experts at NASA say. In fact, they say sunglasses can give a false sense of security, that it is OK to look into the sun if they are dark enough.
The problem is that no pair of sunglasses is dark enough to block the sun's harmful rays.
Optometrist Josiah Young had this to say: "If you use regular sunglasses you could possibly do some permanent damage to your retina."
Instead, Young said, search for NASA approved cardboard glasses, with an "ISO" logo.
"I would go off the official NASA recommendation and use one of their eclipse viewing shades" he said.
Where to find safe glasses
Many libraries and eye doctor offices have been handing out officially approved glasses free of charge, but some of them report they are running out.
You might be able to purchase official glasses for less than $5 at:
Some grocery stores
Toys R Us
Amazon (but see caution below about third-party vendors)
These stores are selling official ISO approved glasses. However, they are selling out fast, and may no longer be in stock in the coming days. You may wish to call your local store first.
For NASA's full list of recommended glasses, CLICK HERE.
NASA, meantime, has issued an alert about glasses sold by third-party vendors online, where you can't guarantee they are the real thing and meet the sun blockage standards. It has reports of some glasses using counterfeit NASA and ISO logos.
Amazon has said that the glasses it sells directly all meet NASA guidelines, but it cannot guarantee the same with all its third-party vendors.
Can't find glasses? What then?
Finally, if you can't find glasses anywhere (they are selling out at stores in hours), Young said welding glasses can work in a pinch.
"If you have welding glasses, you can use shade 14 or darker," he said.
However, Young and NASA warn that standard arc welding glasses might not be dark enough: They must say shade 14.
With any type of glasses, you should not be able to see anything around you when looking through them. If you can make out trees, cars or houses, the glasses are not dark enough.
Safe, old school approach
Finally, if you can't find glasses, or simply don't trust any of them, optometrists say you can make an old fashioned projector, by putting a pin hole in a piece of cardboard and watching the sun's shadow.
You can easily find instructions online on how to make them. A shoebox can work, but just two pieces of cardboard held a distance apart can work too.
You watch the projected image, with no risk of sun damage.
Whatever you decide to do, remember that cheap sunglasses can be worse than nothing at all, as they may encourage you to look directly into the sun.
So don't hurt your eyes and don't waste your money on glasses that won't protect your eyes.