For most of history, humans rose with the sun and slept when it set. Enter Thomas Edison, and with a flick of a switch, night became day, enabling us to work, play and post cat and kid photos on Facebook into the wee hours.
According to a new study of mice led by a Johns Hopkins biologist, however, this typical 21st- century scenario may come at a serious cost: When people routinely burn the midnight oil, they risk suffering depression and learning issues, and not just because of lack of sleep. The culprit could also be exposure to bright light at night from lamps, computers and even iPads.
The study as the researcher explained involved mice because mice and humans are very much alike in many ways, particularly the ipRGCs [intrinsically photosensitive retinal ganglion cells] they have in their eyes that activate by bright light affecting moods, memory and learning affect humans too.
The experiment involved exposing mice to 3.5hours to light followed by 3.5hours of darkness. The result affirmed that light caused the mice to exhibit depression-like behaviours including apathy towards sugar or diminished cognitive abilities. On the contrary, when injected with anti-depressants, it mitigated these symptoms.
Although it might not be possible to confine to complete darkness at night but swapping intense light bulbs with the dim bulbs and basically using only what you need to see might be helpful in not adversely affecting your mood or cognitive functions.