Yes, blue-blocking sunglasses do have solid research behind them for improving sleep for some people. In 2009, a study was done with adults who have trouble sleeping at night; they wore amber sunglasses three hours before bed, which reduces the blue light coming in from electric lights as well as TV and computer monitors. Not only did blue-blocking glasses improve the quality of their sleep, but it also improved mood, researchers reported in the journal Chronobiology International. (http://www.ncbi.nlm.nih.gov/pubmed/20030543)

As you may know, blue light affects our circadian rhythms more than any other kind of light. When we view too much blue light—or view it at the wrong times—the result can be a skewed daily rhythm of sleep and wakefulness. In particular, people who work the night-shift can benefit from blue-blockers when they are exposed to sunlight in the mornings, as this prevents their circadian rhythms from resetting to a morning routine. Some studies suggest that this, along with viewing blue-green light in the evenings, allows them to adapt to a permanent night shift. (http://www.ncbi.nlm.nih.gov/pubmed/19637050)

If you don’t work the night shift and usually get some sun exposure in the mornings, you may still experience better sleep if you limit exposure to blue light in the evenings. This doesn’t mean you have to wear amber sunglasses all the time. Instead, try limiting your TV watching within three hours of bed. If you do a lot of night computing, try using free software like F.lux, which automatically shifts your computer monitor’s light output to warmer side of the spectrum once the sun goes down. (http://edition.cnn.com/2010/TECH/05/13/sleep.gadgets.ipad/index.html?hpt=C1)