You heard me mention color temperature before, and the effect of watching TV or reading on the iPad before bed (See Sleepy Yet? — How Light from Electronics Effects Sleep), 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.