A preliminary study on the effect of mobile device backlight spectrum variation on the quality of sleep among undergraduate students

Abstract

A majority of the college population uses mobile devices on a daily basis. Furthermore, sleep quality in undergraduate students tends to be overlooked, yet it is an essential aspect of college academic life. All mobile phones have a default backlight when in use. The light itself resides in the blue-light wavelengths. We aim to identify particular aspects of sleep quality and the association with smart-phone use, as influenced by red-light filters on the screen (opposite side of the blue-light spectrum). Apple iPhones have a feature called “Night Shift Mode”, which changes the lighting on the screen, shifting to a softer red color from the default blue color backlight, at appropriate and respective times of the day. Previous literature has analyzed the relationship between alertness and blue light on screens, but there is limited research addressing red light usage as an aid to sleep quality. We predicted that the switch between blue light to red light will increase the quality of sleep, by eliminating the increase in alertness associated with blue light. We followed “wake peaks” (number of disturbances during sleep recorded) and the number of hours of sleep as our dependent variables and controlling variable, respectively. Results suggest that there is no significant positive correlation between the implementation of red-light spectrum colors as the backlighting and the increase in the quality of sleep. Additionally, there was no significant change in the duration of sleep time with the implementation of red-light spectrum colors as the backlighting. This suggests that there may be other variables accounting for variations in sleep/wake cycles and sleep quality in addition to the retinal stimulation and increased alertness associated with blue light.