Self-luminous devices, such as computers, tablets and cell phones can emit short-wavelength (blue) light, which maximally suppresses melatonin. Melatonin is a hormone that starts rising approximately 2 hours prior to natural bedtimes and signals darkness and sleep to the body. The present study extends from previously published studies showing that light from self-luminous devices suppresses melatonin and delays sleep. This is the first study conducted in the home environment that investigated the effects of self-luminous devices on melatonin levels in adolescents (age 15–17 years). Results show that 1-hour and 2-hour exposure to light from self-luminous devices significantly suppressed melatonin by approximately 23% and 38% respectively. Compared to our previous studies, these results suggest that adolescents may be more sensitive to light than other populations.