Hrm

A study has found a link between difficulty sleeping and evening use of brightly lit devices... such as computers.

http://www.cnn.com/2010/TECH/05/13/sleep.gadgets.ipad/index.html?hpt=Sbin

I often have trouble getting to sleep, and often go straight from using the computer - a last check of email or game playing - to bed.

Coincidence or causation?

Of course, around here "day" varies from roughly eight to sixteen hours of sunlight (from deep winter to full summer), which probably doesn't help either. Sometimes I'm getting home not long before dark and sleeping through the entire period of darkness would be rather impractical. Going without light for the balance of that period would be equally so. In the summer, I'm going to spend at least some time trying to sleep when it is still daylight outside.