Blue light apparently delivers the wavelengths needed to regulate our circadian rythmns, according to research described in Science Daily.

Blue sky is a mixture of wavelengths dominated by short wavelength light that gives a blue visual sensation. According to Mark Rea, Ph.D., LRC director, the circadian system is essentially a blue sky detector.

“Blue sky is ideal for stimulating the circadian system because it’s the right color and intensity, and it’s on at the correct time for the right duration — the entire day,” said Rea.

LRC is the Lighting Research Center at Rensselaer Polytechnic Institute.

They performed a study in which they exposed elderly people to blue light, and found that the subjects slept more between midnight and 6 a.m.

We’re not meant to be indoors all day. No wonder so many of us aren’t getting enough sleep.

I wonder, also, about the effect of wearing sunglasses . . .