When the elderly insomniacs were exposed to four hours of bright artificial light near the middle of the day (ten o’clock to noon and two o’clock to four) for four weeks, their melatonin secretion rose “to levels similar to those in the young control group, ” says the report.
ويبدو ان هذا النقص في التعرُّض للضوء يشوِّش الجسم ؛‏ فلا يميِّز بين النهار والليل ،‏ مما يؤثر كما يعتقد الباحثون في نوعية النوم .‏