Sleep glasses block 100% of blue light and should be worn in the hours before bedtime. Doing this helps your brain produce melatonin by blocking out the blue light to let your brain know that it is late/dusk. Before electronics, our circadian rhythms would sync naturally with the sun. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.