There's another great advantage to turning off the computer an hour before bedtime. I not only sleep better, i wake better.
The computer is such a seductive date in the evening. Just one more e-mail, one more Google, one more Facebook. I break this addiction one evening at a time, knowing that the craving lies in wait with its oh-so-logical rationale of "doing just one more thing." I have to keep my eye on the long-term benefit rather than the short-term gain that turns out to have a hidden loss (of sleep and then morning alertness) associated with it.
I know very good and well what my bedtime is--10:00 p.m. Dullness sets in an hour beforehand. As a "morning person," i can work so much more efficiently in the morning. If i'm with a group of people, i become quiet at 9:00.
Ostensibly i want to turn off my computer by 9:00 p.m. because i want to have time to meditate. By that hour, i need a sort of rote meditation, such as loving-kindness, because my mind is moving slowly. In fact, my biorhythm makes 7:30 p.m. a better meditation time, thereby decreasing my evening computer contact even further.
My sweetie watches TV from 10:00 to 11:00 every night and has bad dreams 5 nights out of 7. My dreams are sometimes sweet, occasionally funny, and, once in a while, helping figures teach me something or assist in solving problems. The Buddha said that sweet dreams are one of the benefits of loving-kindness practice. Maybe this intention will guide me out of my evening dream-state on the computer.