Solar eclipses are rare and spectacular events.  On August 21st a solar eclipse will be largely visible throughout a wide area of the United States. Many people are attracted to this phenomenon as well as scammers willing to take advantage of those people.
Viewing a solar eclipse without protective glasses is extremely dangerous and can result in serious damage to your eyes.  Regular sunglasses will not protect your eyes while watching an eclipse.  The only way to safely observe this event is to use specially created eclipse glasses.  Fortunately, there are many places that you can purchase proper eclipse glasses. Unfortunately, there are many scammers who are selling defective eclipse glasses that will provide little or no protection whatsoever.
The American Astronomical Society has a list of Reputable Vendors of Solar Filters & Viewers which lets you know both the trustworthy manufacturers of effective eclipse glasses as well as where you can buy them.  Here is a link to their website with that information.
Make sure that any eclipse glasses you purchase carry the manufacturer’s name and address on the glasses and that they are on the approved list. Don’t take the risk of buying eclipse glasses from any company that is not on the American Astronomical Society’s list.