It’s 3am. The cold light of my computer screen illuminates my face, highlighting the bags that are forming under my eyes and casting disturbing shadows around my bedroom. You might think that I was engaged in something incredibly important to keep me up so late. But no, the truth is, I am unable to sleep and resign myself to touring the bizarre offerings the internet presents only early in the morning.
On this particular instance of insomniac procrastination, however, the answer to why I am unable to sleep randomly appears on my monitor. I blink and rub my eyes a little – just to make sure I’m not seeing things. The answer to my problem, ironically, is the problem itself- the computer monitor.
Research, published in the Journal of Applied Physiology, has shown that the light emitted from LED-based computer screens has a strong affect on the circadian rhythm – the biological clock that our bodies use to regulate many bodily functions. Melatonin is one chemical that regulates the circadian rhythm. In the evening, levels of melatonin levels rise, resulting in the drowsy feeling we get that signals the time for bed. In the morning, when levels start to drop, melatonin wakes us from our slumber. The circadian rhythm is 24 hours long, and is dependent on light signals from the outside world to create this regularity.
The human circadian rhythm turn out to be particular sensitive to shorter wave lengths of light, and it is just this sort of light that is emitted in copious quantities from LED monitors that are fast becoming widespread around the world.
To test what effect computer monitors were having, the scientists subjected 13 volunteers to five hours of exposure to computer light before bedtime. Over a period of 2 weeks, melatonin levels were significantly lower in the evenings. The subjects also performed much better on concentration and attention tests.
You might think this is good news. The computer monitor, as well as an access point to a near-infinite world of information also gives you more hours in the day in which to be active. No more wasting seven or eight pointless hours doing nothing each night.
Unfortunately, low levels of melatonin can have several harmful effects. For one, melatonin has been shown to be a cancer suppressant. Night workers, who spend the majority of their waking lives in artificial light, have an increased risk of breast and bladder cancer. Depression is also commonly associated with low melatonin levels. In fact, many neurological conditions, such as ADHD and bipolar disorder, have been successfully treated with melatonin supplements.
The best thing you can do, I guess, is to get off the computer once in a while, especially at night. You now have permission to stop reading and go out enjoy the summer sun while its still here.
Cajochen C, Frey S, Anders D, Späti J, Bues M, Pross A, Mager R, Wirz-Justice A, & Stefani O (2011). Evening exposure to a light-emitting diodes (LED)-backlit computer screen affects circadian physiology and cognitive performance. Journal of applied physiology (Bethesda, Md. : 1985), 110 (5), 1432-8 PMID: 21415172