As I’m writing this post at 9:30 PM, using my computer is likely to keep me up later into the night. It’s not so much the activity or the content that’s overly stimulating, but the type of computer screen that might prevent me from falling asleep. The newer, brighter backlit LED screens that are almost commonplace with computers these days (especially laptops and tablets) have a much higher level of blue light (460 nm), which is known to have stimulating properties on the circadian system. A study published in the Journal of Applied Physiology showed that subjects who used backlit LED screens had higher rates of attention, wakefulness, and declarative memory compared to subjects who used conventional computer screens. On the flip side, melatonin levels were significantly supressed. As you may know, melatonin levels go up as you’re falling asleep.
This has huge implications since many people (including me) use these type of screens while working later in the evening. It may be great during the day so that you can be productive and get more work done, but it’s counterproductive in the evening hours, especially just before bedtime.
Notice also that most of the newer appliances, traffic lights, cars, toys, and even medical equipment, have LED lights, which are significantly more intense than standard lightbulbs. If you have a few electronic appliances in your bedroom, it’s likely that once you turn the lights out, three or four LED lights can light up your entire room, shining much brighter than many night-lights. I cover my LED lights with black electrical tape.
For some reason, driving has been a bit more annoying for me lately, especially in local traffic, and I realized that it may be due to the fact that I have to look at the very bright LED brake lights on the car in front of me, which makes me squint. It just barely seems to give me a headache, sort of like a very mild migraine. I find myself squinting, and I know that my iris is closing down to shut out the light, kind of like clamping down on the aperture on a camera. This would likely stimulate your sympathetic nervous system (your fight or flight response).
The traffic lights bother me a bit too. If all these little things bother me, I’m sure they’re bothering many other people subconsciously, and it will manifest in different ways. It’s also likely to significantly disturb sleep for millions of Americans.
Do you work with backlit LED computers just before bedtime? Do the brighter LED light bother you too?