Last week's BBC documentary on Horizon gave interesting insight into how we can improve our sleep. Light levels, which are linked to melatonin production (a hormone in our brains), have been measured in experiments on the documentary (Ref: “Body Clock: What makes us tick”. See a link to the BBC programme below). According to the Horizon programme, in evolutionary terms our lifestyles are extreme. We are not getting as much natural outdoor light (by a long way), as our hunter gatherer ancestors. Being indoors, on public transport, in cars; being exposed to the blue artificial light from electronics especially after sunset. We follow daily schedules which force us all to live by the same time clock, not how we were built (our genes determine whether we are morning or night owls), so our bodies get confused.
The documentary suggests we can take back control of our sleep by getting natural light from outdoor activities as much as possible. Also, artificial and blue light from TV and electronic gadgets blocks melatonin and sleep. The brain is alert with cortisol and adrenalin levels heightened from TV viewing. Research supports switching off the TV, and electronic gadgets at least 45 minutes before bedtime.
https://www.bbc.co.uk/iplayer/episode/b0bn5ys4/horizon-2018-9-body-clock-what-makes-us-tick