以手机为代表的电子设备的过度使用已经得到越来越多的关注，我们前期的研究也证实其可能引发多种睡眠问题。然而其中的机制尚不明确，可能与夜间电子设备屏幕LED光中富含的蓝光对昼夜节律的影响有关。既往针对屏幕光暴露的研究中，使用手机作为研究工具、比较不同暴露时长及短期和长期影响、探索对昼夜节律基因表达影响的研究尚缺乏。本研究以健康青年人为受试者，采用随机、平衡设计，分别从光谱（带蓝光或滤蓝光）和时长（2h或4h）两个角度，探索手机屏幕光暴露对睡眠（睡眠结构及脑电功率密度）、昼夜节律（褪黑素和皮质醇分泌、皮肤温度）、警觉性和认知功能（注意力、反应速度、记忆力）的影响，并对短期（1晚）和长期（5晚）影响进行比较。本研究亦从分子层面上检测昼夜节律基因表达可能的改变及其与上述指标的相关性，以探索手机屏幕光暴露对睡眠、昼夜节律和认知功能的影响机制，为针对手机屏幕光暴露潜在不良影响的有效预防措施提供理论依据。

The excessive use of electronic media, such as mobile phones, has raised great concerns. As confirmed by our previous study, excessive use of mobile phone has adverse impacts on sleep. However, the mechanism underlying the association between mobile phone use and poor sleep outcomes remains unclear. It may be contributed by the blue-enriched LED emitted from the screen of electronic media on circadian rhythms at night. In previous studies regarding screen light exposure, there are few studies using mobile phones as research tools, comparing the effects of different duration or short-term and long-term exposure, or exploring the effects on circadian rhythm genes expression. In this study, healthy young people will be recruited to explore the effects of screen light exposure of mobile phone on sleep (sleep architecture and EEG power density), circadian rhythms (melatonin and cortisol secretion, skin temperature), alertness and cognitive function (attention, response speed, memory), as well as short-term (1-night) and long-term (5-night) effects from the perspectives of spectrum (with or without blue light) and duration (2h or 4h) with randomized and parallel design. What’s more, the possible changes in circadian rhythm genes expression will be also detected at the molecular level together with their relationships with other outcomes, in order to explore the mechanisms of the influence of mobile screen light exposure on sleep, circadian rhythms and cognitive function. The completion of this proposed study may provide fundamental evidence for the development of management strategies for the consequences of excessive mobile phone use and its related light exposure.