PS. I took melatonin for a while in an attempt to normalise my circadian rhythm. I discontinued that experiment quickly – it made me sick as a dog.
> Inexpensive sunglasses with orange-tinted lenses block blue light …
I want rose-coloured glasses.
> The 1998 discovery of a new photoreceptor in the eye—which later turned out to be especially sensitive to blue light—revolutionized the way we think about how circadian rhythm is entrained.
Aagh! This has nothing to do with circadian rhythm. The new photoreceptor can’t see anything until the lens of the eye is replaced in an operation for cataracts, because the lens of a normal eye blocks the wavelengths that this photoreceptor is tuned to. At least, that’s what I heard at the time.
> blue light may be particularly potent in mitigating depression and other maladies of mood.
So blue light stops you from getting the blues. I don’t believe it.
> For many years it was thought that social interaction was the major force involved in resetting humans’ internal clock
For many years they might have been right.
> From 1995 until 2001, Brainard and his colleagues tested 72 healthy men and women in more than 700 experiments to determine the strongest wavelength for suppressing melatonin secretion. The result confirmed a slightly earlier Japanese study on mutant mice, showing that the blues are the most important wavelengths for entraining the circadian system. Cones, the color receptors, have a peak sensitivity in the greens, at 555 nm. For the rods, the peak comes at 507 nm. Across 10 published studies on humans, rodents, and monkeys, the peak sensitivity of the melanopsin receptors appears to span 459–485 nm.
Worth looking up, perhaps. Oh, he wrote 83 papers on the topic.
> The irony of blue as an environmental agent is that before the industrial age, it was merely a color. The unnatural lighting conditions we created turned it into …
Now they’re calling a blue sky “unnatural”. Ridiculous.
> The aim of this study was to test if the three cone visual system is the primary ocular photoreceptor input for human circadian regulation by determining the effects of different wavelengths on light-induced melatonin suppression. Healthy subjects with stable sleeping patterns (wake-up time 7:30 AM ± 12 min) and normal color vision were exposed at night to full-field 505 nm or 555 nm monochromatic stimuli or darkness for 90 min. Plasma collected before and after exposures was quantified for melatonin. Subjects exposed to 10 irradiances at 505 nm showed no significant differences across mean pre-exposure melatonin values. A curve fitted to the melatonin suppression data indicated that 9.34 × 10^12 photons/cm^2/sec induced a half-saturation response (ED50) while 6.84 × 10^13 photons/cm^2/sec induced a saturation melatonin suppression response. Further, a dose of 4.19 × 10^13 photon/cm^2/sec at 505 nm was significantly stronger than an equal photon dose at 555 nm for melatonin suppression. These data demonstrate that the cone system that mediates human vision is not the primary photoreceptor system to accept light stimuli for melatonin regulation.