I use f.lux during the day on my MBP, iPad, and iPhone at 5500K to (attempt) to cut down in excess blue light (more than what is found in sunlight) during the daytime.
After sunset, I set f.lux to 2700K (3400K on screens that only go down that far) and put on blue-blocking glasses.
For screens I can't control, I'm thinking about getting some Gunnar glasses.