Every cell of our body needs information about the current time of the day, that’s why our light viewing behavior has the strongest effect on the capacity to fall asleep and have a good night sleep.
The suprachiasmatic nucleus, which is our circadian clock, is deep in our brain and it doesn’t have access to light so the neurons from the eye (melanopsin ganglion cells) communicate with this central clock. So there’s a behavior everyone should adopt, including blind people: staying in the sunlight for 2-10 minutes every morning. This does two things: it triggers the timed release of a healthy level of cortisol (which offers wakefulness and ability to focus during the day) and it also sets a timer for the onset of melatonin (sleepiness hormone which is inhibited by light). These cells are very hard to activate early in the day and easy to activate late at night. But even if it’s cloudy, there is a lot more light you can get from looking at the sky than your phone or computer. The distance between the light exposure in the morning and the sleepiness is about 14 to 16 hours.
This exposure also has mood elevating effects because it triggers the activation of dopamine. Cortisol levels are also affected by this light exposure. David Spiegel and Bob Sapolsky showed that if that cortisol pulse shows up later in the day (especially at 8 or 9 pm) it's associated with depression. By shifting that cortisol pulse earlier, you ameliorate some of the symptoms of depression and because of the dopamine release, an overall mood enhancement.
The inverse of all this is also important: as you approach the evening or night time and you want to go to sleep, that is a time to start avoiding bright lights of any color, not just blue light, and if possible to place whatever lights are present in your environment lower in your visual field. Sammer Hattar (National Institutes of Mental Health) showed that bright light exposure of any wavelength between the hours of about 11 pm and 4 am caused a serious disruption in the dopamine system (lowering of mood, difficulties learning).
Light, exercises, eating early in the morning and social cues (interacting with people), are four things that time our circadian biology and align us for sleep. Blind people do this a little bit differently: some blind people actually still retain these so-called melanopsin cells, but people without eyes at all (burn victims) use social cues and exercises.
If you are waking without an alarm clock, two hours before waking up your body temperature is close to or at its lowest point. If you view light in the hour or two before that temperature minimum, it's going to have the quality of delaying your circadian clock and make you want to stay awake later and make you want to sleep in later the following nights. However, if you view light in the hour or so immediately after the temperature minimum, it’s going to shift your clock in the other direction.
Sleeping issues are sometimes treated with sleep aids, supplements or prescription medications. One of the most frequently used sleep aids is melatonin, despite its side effects. One of the most alarming side-effects is puberty suppression. Our bodies naturally produce melatonin and the melatonin system is closely linked with GABA inhibitory neurons in the hypothalamus. Additionally, the melatonin rhythms of young children are not as phasic. Melatonin also has strong effects on the sex hormones, like estrogen and testosterone. Experiments have shown that if you inject Siberian hamsters with melatonin, or you put them into short days - increasing the amount of darkness and decreasing the amount of light - their testicles shrink in size. In females of the same species, they leave estrus, they stop cycling and they don't have menstrual cycles.
Examples of sleep supplements include magnesium threonate and magnesium bisglycinate, which are transportable across the blood-brain barrier; so 200 to 400 milligrams, about 30 minutes before sleep can be a powerful sleep aid. A dose of 200-400 milligrams of theanine can also create a kind of a hypnogogic state that can help you fall asleep by turning off your thoughts. People who suffer from sleepwalking or night terrors should avoid it because it can create very vivid dreams. Apigenin is a derivative of chamomile but it acts as a chloride channel agonist, so it essentially helps shut down the forebrain by hyperpolarizing neurons.
Hypnosis and Yoga Nidra, both fall under the umbrella of the non-sleep deep rest protocols. Yoga Nidra includes 20 or 30 minutes a day, lying down, doing a body scan. It involves some long exhale breathing which is very relaxing to the nervous system and really allows the mind to enter one of these pseudo-sleep states. It's a zero-cost tool that has enormous effects on not just accessing sleep and calm, but enhancing rates of neuroplasticity.
We think we have to turn off our thoughts completely, like a switch, but the transition to sleep involves allowing our thoughts to become fragmented and ourselves to become relaxed, then the brain enters the state where space and time are very fluid and not under our conscious control.
These are definitely things that we can learn from!