The American Astronomical Society is advising buyers to beware of fake glasses being sold ahead of the total solar eclipse. The society says the phony glasses and handheld solar viewers are stamped with the ISO logo and may look real. But they don't have proper filters that block all of the Sun's harmful rays. Glasses that appear hazy, out of focus or not dark enough should be tossed out. Also, true solar filters will only allow you to see solar light through them, If you see an indoor light…the glasses are no good.
The society has a list of trusted vendors and tips on safely viewing the upcoming eclipse on its website. NASA has also posted several safety tips for viewing.
The full solar eclipse will be visible across the country on August 21.
Source: Geekwire