Sleep is a real pain...you take it for granted when it happens but as soon as it doesn't you're miserable. So one of the great non-medical interventions is blocking blue light. People have come to rely on using electronic devices often before bed. There are studies that show this artificially tricks the brain into believing it's still daytime so it doesn't get sleepy. It's a little different than reading a book with ambient light or even watching a TV across the room because you're looking directly into a light so nearby. Anyway there was a study of people with bipolar where they gave them blueblocker sunglasses and they use them a few hours before bed. It didn't work for everyone but I think it was about half reported success. Some people didn't like it because they started getting sleepy too early but other than that no negative impact. You can just order a pair pretty cheap from amazon. Also for laptops etc there are specific programs that will cut the blue spectrum emission but since you use a kindle I doubt that's an option but if you have a paper white you might want to cut the light before bed and if you have a fire try the sunglasses.