1a. If you must use a computer screen before bed, install F.lux (http://stereopsis.com/flux/). As the sun goes down, Flux adjusts the color warmth of your monitor to make it friendly as sunlight diminishes.

It takes a little to get used to, but its completely awesome once you are using it. When you disable it during the night and see your monitor jump to a bright, blinding blue shade you realize how painful it is on your eyes.