Are you the parent of a teen? What time does that teen's school start? There's good evidence that teens
sleep schedules can have a profound impact on their learning and their emotional wellbeing.
This 2001 article covers what was known then, and generally recommends that people between the ages of 11 and 18 get about 9 hours of sleep, without starting the academic day before 8:30.
Here is a high school sleep fact sheet from 2003, with a lot of good links.
What to do? Consider starting the teen (middle school and high school) day at 9:00 am. Consider getting blackout curtains for your teen's bedroom windows (I haven't done it yet, but it is on my list), to allow the teen to sleep as much as she needs.
I know that is hard--for me, I think, yikes, the day is half over. But