How Light affects Melatonin and Sleep
You heard me mention color temperature before, and the effect of watching TV or reading on the iPad before bed, but here’s why it’s important. This WebMD article examines the hormone melatonin, which helps regulate sleep & wake cycles (the circadian clock). Melatonin production in the body is triggered by darkness and inhibited by light, and that explains why we have trouble with jet lag, shift work, and winter months with fewer daylight hours.
This Wikipedia article describes light therapy and melatonin supplements as treatment for sleep disorders like insomnia. It also describes the light color temperature, from the warm yellow of incandescent light bulbs, to blue light of the new fluorescent and LED bulbs (or the bluish tint of the iPad and TV screens).
One way to fool the body into producing melatonin earlier so you can go to sleep earlier is to select warm-color light bulbs and have them dimmed in the evening. Another way is to wear DARK AMBER or ORANGE sunglasses in the evening to block blue light (short light wavelengths). And of course, that’s why sleep experts advise against using a computer or watching TV shortly before bed.
Because my wife and I often watch TV immediately before bed, and she likes to look at videos of our granddaughter on her iPad then, I checked the iPad Settings and found a way to dim the backlighting intensity and set it to somewhat adjust automatically depending on the ambient light. Go to Settings / Brightness & Wallpaper.
I’d also like the iPad to change the color temperature at night but found nothing native in the iPad, so I searched for a reliable iPad app for that. I found iJetlag and TheSleepApp but was disappointed with both of them. One even used the wrong color of light to encourage melatonin production and encourage sleep.
Additional sources of sleep information include the two articles on this site by PhD sleep consultant Bruce Meleski (Sleep Balance – Your Path to Better Sleep and Brain Entrainment for Better Sleep and Health) and in Jeanie Wolfson’s article on Sleep: Timing of Melatonin, Light, Dark, & Use of Other Aids. Wolfson lists many suggestions for improving sleep, including these few:
- Keep bedroom dark or wear an eye mask.
- Keep room cool and feet warm.
- Find a mattress that works for you, trying harder, softer, coil, foam, gel, waterbed, or hammock.
- Block distracting sounds with white noise.
- Use lighting controls to simulate dawn before alarm sounds.
- Don’t watch TV, use a computer use, or do homework within an hour of going to bed.
- Avoid caffeine and snacks that can cause a blood-sugar drop during the night.
- Establish a strict sleep/wake schedule.
- Exercise regularly.



















Light therapy works for 90% of users and this one time investment intrigues more and more people. Light therapy seems to be a universal solution and you can now own acne lights for home use.
Here’s a great resource about the affects of Light on Sleep Quality and General Health:
Light & Health Research Foundation (SOLG) — http://www.solg.nl/
CLICK the British flag at top/right for an English version.
Also, I posted a link to my Economic Value of Good Sleep article in a Linkedin group on Light Therapy, and it has started a discussion of sleep benefits among sleep experts worldwide.
Douglas Steel pointed me to the website for the National Sleep Foundation (www.sleepfoundation.org) and several statistics there, but I found them less than credible and responded:
Dear Mhealthtalk,
This might be off topic, however, Dear Mhealthtalk,
I was wondering on a similar note,, The patio or the backyard is a place where the family can entertain guests, hold parties or just hang out with each other. It can be a place for dining, cooking barbeque, playing cards or maybe even swim in a pool. All of these activities usually take part during nighttime that is why the right kind of patio lights should be chosen to provide the right amount of lighting in the patio.
Great Job!
Thanks
Incandescent bulbs are so called because of the heat produced. Incandescence means to glow with heat. The tungsten filament is found inside a void within the bulb. When energy is pumped through the wire, the electrons react and there is resistance. Then, the filament will get so hot it will glow.
(Editor: The light from a hot filament is somewhat like the light from a campfire, i.e. warm coloration, as opposed to the blueish or greenish light of fluorescent lights. I also removed a potentially dangerous link.)