Sleep is an active state which is evoked by many complex neurological processes. It is regulated by the homeostasis sleep/wake system and circadian rhythm. The most important environmental factor that affects the waking/sleeping cycle is sun light. Exposure to blue light, especially in the evening, has negative impact on children's sleep. Sleeping is mandatory for the physical, emotional and mental health of children and adults. Sleep related problems are one of the most frequent reason parents ask for a pediatrician’s help. Although parents are more concerned about the child’s sleep than other processes of a child’s development, in general they do not know enough about sleep hygiene and healthy sleeping habits. Even though the prevalence of sleep disorders in children is high, it is often overlooked by healthcare professionals. From around the world we receive data how adolescents do not get enough restful sleep, leading to cognitive, social and health problems. Behavioral sleep disorders are directly related to sleep hygiene which treatment requires affect changes in behavior as well as providing optimal environmental conditions. This can sometimes present a great challenge.