Sleep is independently linked with longevity, something I pay attention to. The “blue light” linked with televisions, computers, and smart phones, to name just a few, may be contributing to insomnia and, indirectly, to cardiovascular problems. Lead researcher in a study to evaluation the impact of “blue light,” Dr. Ari Shechter has been quoted as saying: “Insomnia is often characterized by physiologic hyperarousal, which may account for the relationship between poor sleep and cardiovascular risk. Going forward, it will be interesting to examine whether this blue-light blocking approach [using amber-tinted lenses] can be useful for improving cardiovascular outcomes like hypertension in individuals with poor sleep.” Apparently, some smart phones can be adjusted toward warmer amber light at night instead of blue light. I’m checking out that option on my iPhone.