Unless you are an astronomer with special filters on your telescope, you MUST protect your eyes when watching an eclipse. As I discuss in America's First Great Eclipse, in 1878, eclipse watchers viewed the eclipse through "smoked glass" made by holding shards of clear glass over candles or oil lamps. They also used manufactured tinted glass, such as dark blue glass, as depicted in this image from the Colorado Springs Gazette newspaper...looks heavy! Fortunately, in 2017 you can get inexpensive, lightweight paper and polymer glass--in fact, at the link below you can get them for free, just pay for shipping. Cool!