Laptop and monitor screens. Smartphone screens. Hand-held game screens. Digital tablet screens.
Screens emit blue spectrum light, which is well known to shut off the function of the pineal gland in the brain. The pineal gland is responsible for releasing melatonin, a sleep hormone, into the bloodstream in the evening with the dimming of daylight. Endogenous melatonin (that which naturally occurs in the brain) is a critical part of the physiological landscape that allows for sleep. If you encounter even a small amount of blue spectrum light after the sun goes down, you are going to disturb the work of your pineal gland.
That means you need to avoid doing the following within an hour or so of going to bed, if possible:
- Checking email
- Watching movies or television shows on a laptop, portable DVR, smartphone or tablet
- Making Skype video calls
- Playing games on any of these same devices
Television screens may or may not be problematic as one's usual viewing distance from a TV screen may be far enough away to diffuse the emission of blue and other spectrum light.
SLEEP HYGIENE TIP OF THE WEEK: Put away your screens one hour before bedtime. I know, it's hard to do! One of the ways I relax at night is to review the next day's schedule so I know what I am going to be doing. This act is a good one for dissolving anxiety for busy working people, but doing it online in Google calendar is counterproductive. Instead of checking my gCal online, I review and print out the next day's schedule on paper before dinnertime and read my upcoming schedule in that form instead. This way I feel like I can have some control over time management without thwarting the natural melatonin production of my pineal gland.