When I was growing up, I rarely used my home computer for school work. In college and med school, it was more common but I still used it mostly to write papers. However, there has been a huge shift in the way that we consume information and produce work. We now use screens much of the time. Teenagers have the special challenge of too much homework and too early school start times, limiting how long they can sleep at night. I call this phenomenon structural sleep deprivation. Social media and gaming certain can account for some of this, but I also think that teens (and grown-ups) are up late looking at bright screens. The problem with this is that blue-white light emitted from our screens is similar to the light wavelengths from the sun. This tricks our bodies into staying up later by moving melatonin secretion later in the day. In this diagram, light exposure in the PM is indicated by the blue arrow.
The technical term is circadian phase delay and it can result in a phenomenon one sleep expert described as “social jet lag” whereby your body is on a different schedule than school, work, etc, resulting in feeling tired all of the time. So what can you do about this:
- Install f.lux on your computer: f.lux (for Macs), or t.lux (for Windows) is a free piece of software which alters the color temperature of your computer depending on the time of day. After sunset, it adjusts the color of your monitor so it is more yellow and less blue-white– similar to how your lights in your home are different from the sun. I recommend this to all of my teenage patients with insomnia (and their parents) and I use it myself. Best of all, it is free. You can obtain this software at Just Get Flux.
- Reduce brightness on your phone or tablet and use “night mode” if available: If you are working on a tablet or phone, things get a little more complicated. You can manually dim the brightness of your device. Some software allows you to invert the look of your screen to minimize light exposure. Look at this example from Instapaper on my phone. The one on the right is much better for reading at night:
- Android users can try apps like Darker or Screen Filter to dim and/or change the color temperature of their devices. (Thanks to Joe Naylor who provided this tip on Google +!)
- Go on a “light diet” before bedtime: It is really helpful to avoid any screen exposure for 30 minutes before bedtime.
It’s easy to understand how caffeine can affect your sleep. Light has similar, powerful effects. So being conscious of light exposure in the evenings can help you get a better night’s sleep.
Are you sensitive to light? Do you notice that it affects your sleep? Let me know in the comments below.