Vol. 31 (1) 2010 Neuro endocrinology letters

Lack of short-wavelength light during the school day delays dim light melatonin onset (DLMO) in middle school students.

OBJECTIVE: Circadian timing affects sleep onset. Delayed sleep onset can reduce sleep duration in adolescents required to awake early for a fixed school schedule. The absence of short-wavelength ("blue") morning light, which helps entrain the circadian system, can hypothetically delay sleep onset and decrease sleep duration in adolescen.....