NASA is alerting people about unsafe eclipse-viewing glasses as parts of the country prepare for a solar eclipse.

A total solar eclipse, in which the moon entirely blocks the sun, will last for nearly 3 minutes, depending on where in the country you watch. But you shouldnt look at the sun, even during partial and full eclipses, through a camera or ordinary sunglasses, NASA says.

The only safe way to look directly at the uneclipsed or partially eclipsed sun is through special-purpose solar filters, federal websites say, pointing to eclipse glasses and handheld solar viewers as examples of proper devices.

A total solar eclipse will occur Aug. 21 for people watching from parts of the country. Also, a partial eclipse will last for two to three hours and be visible to everyone in North America.

For eclipse glasses, the federal government recommends that people use American Paper Optics, Rainbow Symphony, Thousand Oaks Optical or TSE 17.

Even when wearing eclipse glasses, one should not look at the sun through a camera, telescope, binoculars or other devices, because you could be seriously injured.

Eclipse glasses are unsafe after three years, according to NASA, and shouldnt have scratches or be wrinkled.

NASA also instructs people to use eclipse glasses that have an ISO international standard icon with reference number 12312-2.

Excerpt from:

NASA alerting people to unsafe eclipse glasses - WCVB Boston