These sunny, sweltering days we're experiencing have inspired me to synthesise some recent insights into the science of sleep courtesy of Prof Matthew Walker - a must read is his excellent and shocking book 'Why We Sleep' and for a brief overview see his TED Talk , also articles by Peter Attia MD, podcasts and Dr Rangan Chatterjee here is his podcast with Matthew Walker & Prof Andrew Huberman - try his podcast 'Master your sleep'.

An emerging body of research is now shining more and more light on the role of light itself in establishing and maintaining our 24-hour body clocks - circadian rhythms - that determine so many of our internal systems and processes.

Adenosine, melatonin and cortisol, to name a few, are a handful of the crucial chemical and hormones that are involved in regulating our highly synchronised existences.

We can all struggle with sleep at some point. The effects can be dramatic and harmful to health - both short-term and long-term. Poor sleep may be responsible for as much population ill-health as excessive alcohol consumption or even smoking and alzheimers, cancer, infections, heart attacks, accidents are all crucially increased by too little or irregular sleep. It's perhaps no surprise that since ancient times sleep deprivation has been used as a potent tool of torture!

Exposure to natural sunlight for just 2 to 10 minutes as early in the morning as possible has been shown to confer a wonderfully powerful "anchor point" to our bodies internal rhythms and can significantly contribute to more wakefulness and in turn better sleep. It doesn't even have to be a sunny day. (On that note, light through a window is nowhere near as effective - download a light meter on your phone and compare the two for yourselves).

Conversely, minimising exposure to overhead lights, bright lights and blue-light in the evenings provides a second "anchor point" to double down on the benefits.

On this latter front, although the science behind blue-light blocking itself is in flux,  some may find blue-light blocking filters and devices effective (the picture above is one I use by my bed).  

Some more details are available from The Sleep Foundation.(note there may links to commercial products on some pages - we do not endorse any)