# Research on the Application of the Dynamic Assisted Sleep Light to Smart Mobile Devices
## 1 Introduction
Additionally, in terms of productivity, the workers who use the dynamic light source are also more efficient, and the circadian rhythm of the shift workers is adjusted [10]. In a practical working environment, [PERSON] et al. [11] also studied the effect of a fluorescent lamp dynamic light with a color temperature changing from 3000 K to 4700 K, which was irradiated for 10 h (8:00-18:00) in a working day. Although 83 subjects expressed more satisfaction with the dynamic light, there was no obvious statistically significant difference in alertness and subjective performance compared with static light. According to the literature studied by [PERSON] et al., the effects on melatonin under exposure to a light source below 4000 K are not significant, and the phenomenon of melatonin suppression is obvious at a color temperature above 4000 K, which means that a light source below 4000 K has no obvious effect on melatonin [12]. Through the research, it is evident that the human eye affects the physiological secretion of melatonin and cortisol after receiving short wavelength blue light exposure, resulting in sleep disorder. With the rapid development of science and technology in recent years, people's lives are becoming more and more convenient and comfortable. Still, it also brings people a lot of indirect hazards, meaning that health issues are receiving more and more attention. Because people come into contact with light every day in any job, and light is a necessity of daily life, there has been much research on the influence of light on the human body, and in recent years, the most discussed question is whether light affects sleep quality. However, the results of the study [13] found that exposure to too many indirect light sources can lead to imbalances in the biological clock, circadian rhythm disorders, and delayed melatonin secretion, leading to sleep disorders, which in turn lead to insomnia and other problems. The occurrence of insomnia and sleep disorders also brings a series of serious consequences [13; 14; 15; 16; 17]. In addition, reading, relaxing, and working with electronic devices before going to bed has become a common feature of modern lifestyles. In several studies, the time spent watching the screen has an effect on attention and sleep time. In 2015, in the research of [PERSON] et al., it was found that looking at an E-book e-reader for 4 h before going to sleep would reduce the melatonin secretion of the subjects, delay the biological clock time,and significantly reduce the REM time of the subjects [18]. The results of this study confirm that the longer one uses electronic devices, the more serious the impact on sleep. In 2016, in the research results of [PERSON] and others, it was also found that the average teenager looked at a computer screen and played games for more than 2 h continuously, and therefore sleep time would be significantly shortened [19]. In general, the research report of [PERSON], [PERSON] pointed out that reading e-books or physical books for 2 h at night would not have any additional influence on melatonin secretion under the influence of a day's exposure to sunlight and artificial light [20]. However, in 2013, the scientific research of [PERSON], [PERSON] and others pointed out that when the brightness of a flat screen is below 80 lux and the use time is below one hour, the sleep time of the flat screen user is not significantly different from that of someone using a screen with 1 lux filtered blue light [21]. This is different from other scientific studies where there is significant melatonin suppression in the continuous viewing of electronic devices for more than 2 h and exposure to human light [22; 23; 24]. Following our understanding that the reception of light will affect the circadian rhythm and shift the sleep phase, more literature about the influence of light on sleep and the fact that illumination affects the circadian rhythm is beginning to appear. The light is not only sunlight and indoor lighting but also that from mobile devices.