The use of a red light observed through closed eyes is a new CBT Cognitive Behavioral Therapy to fight insomnia. Its principles are based on the high transmission of the colour red through eyelids, the great sensitivity to light of the retina when it is adjusted to darkness and the mental distraction obtained by the perception and attentive observation of variations of intensity. The prefrontal and occipital fNIRS recordings document this method which is correlated to the sleep EEG state II.