Scientists Confirm Screen Exposure Disrupts Sleep

Prolonged exposure to various screens affects the way retinal cells program our internal clocks, a new study finds.

With the sheer astronomical rise in devices surrounding us, from smartphones and tablets, to flat screen televisions and laptops, it seems our eyes are subjected to more strain than ever before. After all, the average American spends upwards of 4 hours of their waking time in front of a screen. 

Although an arsenal of technology including biometric scanners and indestructible screens are on the rise, we should also be aware of the effect the extra time scrolling, writing and reading, has on our eyes. Now, researchers from the Salk Institute for Biological Studies in California have set out to do just that.

Finding the Link

The research focuses specifically on its impact on our sleep, specifically the ways in which cells in the eyes--intrinsically photosensitive retinal ganglion cells (ipRGCs)--(1) process the ambient light we are exposed to and then (2) respond to this exposure by modifying our biorhythms.

To achieve their results, the team looked at the production of the cells in mice, and found that the response to light exposure from the cells was not consistent, which means that retinal cell regeneration, an important part of the process, could not be sustained. They hope to explore the reasons behind this in future research. 

As the researchers explain, ipRGCs "are indispensable for non-image-forming visual responses that sustain under prolonged illumination", which means that a whole host of sleep-related disorders can arise, or be worsened, by this extra exposure. Knowing why this happens inconsistency occurs wil provide many new clues. 

The Answer is in the Cells 

Ludovic Mure, staff scientists as well as first author on the paper, explains why ipRGCs are such a crucial part of deciding how we sleep at night:


"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."

11 Easy Ways to Reduce Your Screen Time

11 Easy Ways to Reduce Your Screen Time

Too often, when we experience insomnia, disruptions of our circadian rhythms, or even jet lag, we may easily attribute it to stress or lack of sleep, when really all that extra screen time may be the main culprit.

"We are continuously exposed to artificial light, whether from screen time, spending the day indoors or staying awake late at night," says Salk Professor Satchin Panda, senior author of the study. "This lifestyle causes disruptions to our circadian rhythms and has deleterious consequences on health."

As the study seems to indicate, our eyes may be the biggest loser in this age of technology. And though the lure of using devices will continue to increase, with all the access to stimulating information and entertainment they provide, hopefully, people will begin to exercise a bit more caution or restraint armed with new information like this.  


Details about the study appear in an article, titled "Sustained Melanopsin Photoresponse Is Supported by Specific Roles of β-Arrestin 1 and 2 in Deactivation and Regeneration of Photopigment", which was published November 27th in the Cell Reports journal.

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