I'll just point out that artificial light screws with your sleep cycle. Light will depress melatonin production, LEDs are especially effective at this.
I'd also recommend the program flux. It adjusts your monitor color and light based on time and location. It won't beat not having anything electronic on at night of course, but it will visibly sync your computer with the sun.
http://www.nytimes.com/2011/07/05/health/05light.html?pagewa...