Here's how your phone might be disrupting your sleep

Researchers at Salk Institute in the US found that certain cells in the eye process ambient light and reset our internal clocks, the daily cycles of physiological processes known as the circadian rhythm. Now, when these cells are subjected to artificial light emitted by your phones and computers, our internal clocks can get confused, resulting in a host of health issues.

Among the many health issues that this light can cause, a few disorders happen to be among the likes of cancer, obesity, insulin resistance, metabolic syndrome and more. Panda, a researcher said, “We are continuously exposed to artificial light, whether from screen time, spending the day indoors or staying awake late at night. This lifestyle causes disruptions to our circadian rhythms and has deleterious consequences on health.”

When your eyes are subjected to the light, a protein called melanopsin continually regenerates within them, signalling levels of ambient light directly to the brain to regulate consciousness, sleep and alertness. Melanopsin plays a pivotal role in synchronising our internal clock after 10 minutes of illumination and, under bright light, suppresses the hormone melatonin, responsible for regulating sleep.

"Compared to other light-sensing cells in the eye, melanopsin cells respond as long as the light lasts, or even a few seconds longer. That’s critical because our circadian clocks are designed to respond only to prolonged illumination," said staff scientist Ludovic Mure. According to previous studies, it was believed that proteins called arrestins, which stop the activity of certain receptors, should halt cells’ photosensitive response within seconds of lights coming on. The researchers were surprised to find that arrestins are in fact necessary for melanopsin to continue responding to prolonged illumination.

“Our study suggests the two arrestins accomplish regeneration of melanopsin in a peculiar way,” Panda said. “One arrestin does its conventional job of arresting the response, and the other helps the melanopsin protein reload its retinal light-sensing co-factor. When these two steps are done in quick succession, the cell appears to respond continuously to light,” he concluded.