It is almost common knowledge that blue light emissions from electronic devices can effect circadian rhythm. For this reason, insomnia sufferers are often educated about sleep hygiene practices and reducing blue light stimulation around bed time. This means:
turning bedroom TVs off at the wall,
placing the face of your phone down,
using dim red lights for night lights,
replacing bedroom/living area lights with incandescent bulbs (which throw off less blue light than LED + fluoro),
and avoiding bright screens within 3 hours of sleep.
This is because blue light has been shown to supress melatonin production – the hormone that regulates our sleep/wake cycle. One study examining the effects, showed that when compared to green light, melatonin was inhibited up to twice as long, potentially shifting the circadian rhythm by a few hours.
The significance of this other than unwanted wakefulness? Well it is also thought that conditions such as diabetes, leptin resistance (involved in obesity), depression and heart disease may be precipitated under circadian influence. Moreover, recent studies have shown that melatonin may also play a significant role in gut motility, immunity, secretion and inflammation; with melatonin showing the ability to alter gut flora, moderate perfusion across the gut, and reduce inflammation.
This may be significant for conditions such as acne, eczema and psoriasis, as well as other inflammatory auto-immune conditions. As increased gut inflammation and permeability has been shown to induce low level systemic inflammation, triggering conditions of inflammation.
So if ever there was good reason to read a book and head to bed early, your skin may be one!