Why are many teenagers night owls? New findings by Mariana G. Figueiro, a sleep researcher (apparently, there is such a job) at Rensselaer Polytechnic Institute, show that it's the lack of morning light:
Riding in school buses in the early morning, then sitting in poorly lighted classrooms are the main reasons students have trouble getting to sleep at night, according to new research.
Teenagers, like everyone else, need bright lights in the morning, particularly in the blue wavelengths, to synchronize their inner, circadian rhythms with nature's cycles of day and night.
If they are deprived of blue light during the morning, they go to sleep an average of six minutes later each night, until their bodies are completely out of sync with the school day, researchers from Rensselaer Polytechnic Institute reported Tuesday in the journal Neuroendocrinology Letters.
The finding was made by fitting a group of students with goggles that blocked blue light and discovering that their circadian rhythms were significantly affected.